JPH05340502A - Boiler vibration isolating device - Google Patents

Abstract

PURPOSE:To offer a boiler vibration isolating device which has an enhanced effect to reduce the seismic response load not only for a large earthquake but also for a medium or small one. CONSTITUTION:A back stay 5 is attached to the outside of a boiler main body. Two or more elastoplastic elements are connected to a back stay 5 by inner binders 8 and outer binders 7 which located outside the inner binders 8. A steel beam 1a is held between the left and right side inner binders 8. The inner binders 8 are connected together by inner tie plates 10 and the outer binders 7 by outer tie plates 9a and 9b. A gap deltat is provided between the outer and inner binders 7 and 8, so that the inner binders 8 act in a group during a medium or small earthquake and the outer binders 7 join the action during a large earthquake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler steady rest device, and more particularly to a boiler steady rest device in consideration of reduction of response load during an earthquake.

[0002]

2. Description of the Related Art A boiler apparatus is suspended from a supporting steel frame by a suspension bolt in order to allow the thermal expansion of the boiler body during operation. exercise. At that time, a steady rest is provided for the purpose of limiting the relative displacement between the boiler main body and the supporting steel frame within a limit. The limit of relative displacement is piping connected to the boiler body (especially high pressure steam piping)
It is set to protect ducts and ducts.

A typical structure of a conventional boiler steady rest is shown in FIG. The steady rest is configured so that the post 1a in the supporting steel frame is sandwiched by two stoppers 14 attached to the back stay 5 which is a reinforcing member of the boiler body 2a. Boiler body 2 in the "vibration direction" indicated by the arrow in the figure
When a is swung, the stopper 14 contacts the post 1a,
Amplitude is limited. It is well known that the seismic response load is reduced if restraint is performed while a large plastic deformation occurs when an earthquake occurs, and there is an energy absorber in the steady rest of the piping system based on this idea. However, in the steady rest device of the above-mentioned related art, since the strain is concentrated on the root portion of the stopper 14, a large plastic deformation cannot be tolerated and the reduction of the seismic response load is small. As a device that enables greater plastic deformation than the conventional technique, there is an unknown boiler steady rest device (Japanese Patent Application No. 4-133732) shown in FIG. 9 and proposed by the present inventor.
In the above-mentioned invention, since a plurality of elasto-plastic elements 6 that cause deformation in the equal stress beam mode are used for restraining, a large plastic deformation can be allowed, and the above-mentioned drawbacks of the prior art are solved. Through the binder 15 and the tie plate 16, the plurality of elasto-plastic elements 6 all generate restraining force under the same deformation behavior.

[0004]

In the boiler steady rest according to the above-mentioned inventor's invention, all the elasto-plastic elements integrally perform the same deformation behavior, so if the amplitude exceeds the elastic limit, Generates a substantially constant binding force regardless of the amplitude. The restraint force must be appropriate to restrain the displacement when a large earthquake occurs, but this restraint force is too strong when a small earthquake occurs, and the reduction rate of the seismic response load in a small earthquake is also large. small. An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a boiler steady rest device which enhances the effect of reducing the seismic response load against a small or medium earthquake.

[0005]

To achieve the above object, a first invention of the present application is provided between a backstay provided outside a boiler main body and a supporting steel frame for suspending and supporting the boiler main body. In a boiler steady rest device for limiting relative displacement between a main body and a supporting steel frame, the device is constituted by a plurality of elasto-plastic elements that generate a restraining force while performing elasto-plastic deformation behavior, and the elasto-plastic elements are grouped into a plurality of groups. The present invention relates to a boiler steady rest device characterized by being divided into

A second aspect of the present invention is a boiler steady rest which is provided between a back stay provided outside a boiler main body and a support steel frame for suspending and supporting the boiler main body, and which limits relative displacement between the boiler main body and the support steel frame. In the device, the device is composed of a plurality of elasto-plastic elements that generate a restraining force while exhibiting elasto-plastic deformation behavior,
It is divided into two or more groups, and a predetermined interval is provided in the vibration direction between the groups, and the restraining force is generated by the elasto-plastic element of one group up to the trigger amplitude, but the elasto-plastic element of another group is generated above the trigger amplitude Also relates to a boiler steady rest, characterized in that it is configured to generate a deformation behavior to generate a restraining force.

A third invention is based on the above-mentioned second invention.
The present invention relates to a boiler steady rest, which is provided with a trigger mechanism and a lock mechanism for increasing the restraining force by causing deformation behavior of other groups of elasto-plastic elements integrally when the trigger amplitude is exceeded.

[0008]

[Operation] By dividing the elasto-plastic elements into groups and reducing the number of elasto-plastic elements that generate restraining force against the amplitude during small and medium earthquakes, all elasto-plastic elements are integrated and restrained regardless of the amplitude. When the force is generated, the excessive restraint at the time of the occurrence of small and medium-sized earthquake is eliminated. In other words, by changing the number of elasto-plastic elements that generate constraining force depending on the magnitude of the amplitude, that is, the constraining force, in contrast to the amplitude dependence that the constraining force effective for reducing the seismic response load changes according to the amplitude. Correspondence becomes possible. As a result, the effect of reducing the seismic response load is high even for small and medium-sized earthquakes.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concept of the method of supporting the entire boiler apparatus to which the present invention is applied is shown in FIG. 1, and the embodiment of the present invention is shown in FIGS. FIG. 2 shows an example of dividing the elasto-plastic element 6 according to the first embodiment of the present invention into two groups. That is, the middle group that is sandwiched between the posts 1a from both sides and fixed to the two binders 8 that are connected by the tie plate 10 and the binders 8 of the middle group are arranged with a clearance,
It is an outer group fixed to two binders 7 connected by tie plates 9a and 9b.

The lock plate 11 according to the second embodiment of the present invention is shown in cross section in FIG. 3 together with the trigger mechanism. The lock plate 11 is a steel plate having both tapers at the bottom, and the upper tie plate 9a and the middle tie plate 10 of the outer group are provided with an opening slightly larger than the parallel portion dimension of the lock plate 11 and the outer group of the outer group. The lower tie plate 9b is provided with an opening that matches the taper tip of the lock plate 11. Trigger 1
Reference numeral 3 denotes a plate having a protrusion on the upper surface, which is placed so as to narrow the opening of the tie plate 10 in the middle group, and the opening side end receives the lock plate 11, and at this time, the upper protrusion is the lock plate 11. It is in contact with the tip of the taper part. The end of the trigger 13 on the side opposite to the side receiving the lock plate 11 is pressed from above by a presser 12 whose tip is bent outward. The tip of the retainer 12 is bent so as to have a spring effect when the trigger 13 is inserted, and the other end is fixed to the upper tie plate 9a of the outer group.

FIG. 5 shows the proposal of the present inventor shown in FIG.
Amplitude δ and restraint in such an unknown boiler steady rest.
The relationship of force F is shown. The behavior of the elasto-plastic element 6 is perfect
Assuming plasticity, a large-scale earthquake is shown in Fig. 5 (a) when a small-scale earthquake occurs.
The time of occurrence is shown in FIG. In this case all elastoplastic
Since the element 6 has the same deformation, the elastic limit is exceeded.
After restraint, the restraint force is the same regardless of the amplitude. Against this
Then, the elasto-plastic element 6 according to the first embodiment of the present invention is
The relationship between the amplitude δ and the restraining force F when divided into groups is
As shown in FIG. FIG. 6 shows a second embodiment of the present invention.
It does not include a gar mechanism and a lock mechanism, that is, in FIG.
In this case, the lock plate 11 is not provided. In Figure 2
Clearance δ between binders 7 and 8_tShake below
The case of swinging in the width is shown in FIG. In this case, the binding force
Is caused by the elasto-plastic element on the inner side in FIG.
There is only the group, and the binding force F is
The smaller the value, the larger the amplitude δ. Amplitude is δ_tWhen it's over
The result is shown in FIG. δ _tWhen the above amplitude is reached,
The contacts 7 and 8 are in contact and the glue of the outer elasto-plastic element
The restraint force due to the
The behavior changes to the behavior of the solid line. Shown by a solid line in FIG.
Compared to the loop in Fig. 5 (b), the loop is partially missing.
Will be This is because the vibration direction is reversed and spring back
If minutes return, tie plates 7 and 8 that were in contact
Away until the other tie plates 7 and 8 come into contact
The restraining force between the two depends only on the inner elasto-plastic element
This is because it will happen. The seismic response reduction effect of δ and F
Energy proportional to the area of the loop shown in the relationship
-There is a positive correlation with the amount of absorption, and
The smaller the area, the less energy absorption
Become.

What eliminates this lack of loop is a trigger mechanism and a lock mechanism according to a second embodiment of the present invention, which is shown in FIG. FIG. 3A shows the initial set state, and FIG. 3B shows the locked state after the trigger acts. The process in which the trigger 13 operates is shown in FIG. 4, where (a) shows the initial set state,
(B) shows the state where the amplitude reaches the trigger displacement δ _t ,
Each of (c) shows the moment when the trigger acts by receiving the swing back after the amplitude reaches the trigger displacement. In FIG.
Until the trigger 13 acts and locks, a relative displacement occurs between the outer upper tie plate 9a and the middle tie plate 10, and the trigger 13 moves outward in response to the relative displacement. Since the trigger 13 is pressed from above by the presser 12 whose tip is bent outwardly, it moves to the outside, but the return to the inside is blocked by the tip of the presser 12 being engaged. It When the outward movement of the trigger 13 exceeds the trigger displacement, the lock plate 1
When 1 is dropped, the outer and inner elasto-plastic element groups are locked so as to behave integrally.

In FIG. 7, a loop with a small restraining force is formed as shown in FIG. 7 (a) until the trigger is actuated and the lock is generated, but when the lock is generated, the loop from the broken line to the solid line in FIG. Move on to. After locking, all the elasto-plastic elements 6 have the same deformation behavior, so that the loop shown by the solid line in FIG. 7 (b) occurs in the boiler steady rest device according to the inventor's prior application of FIG. 5 (b). It is the same as the loop, and there is no loss of energy absorption due to the lack of the loop.

As described above, according to the present invention, it is possible to perform a constraint that draws a hysteresis loop without energy absorption loss with a small constraint force at a small amplitude and with a large constraint force at a large amplitude. When the present invention is used, by dividing the elasto-plastic elements of the first embodiment into groups,
Corresponding to the amplitude dependency that the effective restraining force for reducing the seismic response load changes according to the amplitude, it becomes possible to perform steady rest using the effective restraining force even during small and medium earthquakes.
Moreover, the trigger mechanism and the lock mechanism according to the second embodiment can perform steady rest by a large restraining force without loss of energy absorption even during a large earthquake.

[0015]

According to the present invention, a plurality of elasto-plastic elements are divided into groups, and when the trigger amplitude is exceeded, the elasto-plastic elements of the other groups are integrally united to generate a deformation behavior to increase the restraining force. By providing the trigger mechanism and the lock mechanism for this purpose, it becomes possible to provide a boiler steady rest having a high effect of reducing the seismic response load for a wide range of earthquake magnitudes from small to medium earthquakes.

[Brief description of drawings]

FIG. 1 is a schematic view of a boiler support device to which the present invention is applied.

FIG. 2 is an explanatory view of an embodiment of the present invention.

FIG. 3 and

FIG. 4 is an explanatory diagram of a trigger mechanism and a lock mechanism according to the present invention.

FIG. 5 is a diagram showing a relative displacement between a boiler body and a supporting steel frame and a restraining force in an unknown boiler supporting structure proposed by the present inventor.

FIG. 6 and

FIG. 7 is a relational diagram of relative displacement and restraining force between a boiler body and a supporting steel frame in an embodiment of the present invention.

FIG. 8 is a perspective view of a boiler steady rest according to the prior art.

FIG. 9 is a perspective view of an unknown boiler steady rest device proposed by the present inventor.

[Explanation of symbols]

1 ... Supporting steel frame, 1a ... Post, 2 ... Boiler body, 2a ...
Water wall, 3 ... Suspension bolt, 4 ... Boiler steady rest (seismic tie), 5 ... Back stay, 6 ... Elasto-plastic element, 7 ... Outer binder, 8 ... Middle binder, 9a ... Outer upper tie plate, 9b ... Lower outer tie plate, 10 ... Medium tie plate, 11 ... Lock plate, 12 ... Presser, 13 ...
trigger.

Claims (3)

[Claims] 1. A boiler steady rest, which is provided between a backstay provided outside a boiler main body and a supporting steel frame for suspending and supporting the boiler main body, for limiting relative displacement between the boiler main body and the supporting steel frame. A boiler steady rest device characterized in that the device is constituted by a plurality of elasto-plastic elements that generate a restraining force while exhibiting elasto-plastic deformation behavior, and the elasto-plastic elements are divided into a plurality of groups. 2. A boiler steady rest, which is provided between a backstay provided outside a boiler main body and a support steel frame for suspending and supporting the boiler main body, for limiting relative displacement between the boiler main body and the support steel frame, The device is configured by a plurality of elasto-plastic elements that generate restraining force while performing elasto-plastic deformation behavior, and the elasto-plastic elements are divided into two or more groups, with a predetermined interval in the vibration direction between the groups, Up to the trigger amplitude, the constraining force is generated by one group of elasto-plastic elements, but above the trigger amplitude, the elasto-plastic elements of other groups also generate deformation behavior to generate the constraining force. Boiler steady rest device. 3. The trigger mechanism and the lock mechanism according to claim 2, wherein when the trigger amplitude is equal to or larger than the trigger amplitude, the elasto-plastic elements of the other groups are integrally deformed to increase the restraining force. Characteristic boiler steady rest device.