JP4885656B2 - Vertical dynamic damper - Google Patents

Description

  The present invention relates to a vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in a diesel engine for a power plant.

  In recent years, for example, a power plant using a low-speed two-cycle diesel engine with a rated rotational speed of 100 to 200 rpm and an output number of several thousand kW to 50,000 kW has attracted attention because of its low fuel consumption and easy maintenance. ing. This type of large diesel power generation engine has a check platform with a grating beside the diesel engine because a person needs to climb to the top of the diesel engine for inspection and inspection. However, since the inspection platform vibrates up and down in synchronization with the vibration of the diesel engine, cracks that may be caused by fatigue have occurred in the welded portion of the platform.

  As a vibration isolation method for a large-sized low-speed diesel engine, changing the ignition order of cylinders or applying various dampers has been studied (for example, see Patent Document 1). However, in order to change the firing order of the cylinders, not only does it take a considerable amount of time to study, but there are cases where an appropriate firing order cannot be found. The damper described in Patent Document 1 employs a pendulum motion type weight for damping, and thus is effective for rolling, but unsuitable for pitching.

Small dynamic dampers are applied to power transmission systems for automobiles and bridge structures, but there are many problems. For example, although the dynamic damper disclosed in Patent Document 2 is compact, there is a risk of liquid leakage because a viscous material is accommodated in the casing. Moreover, although the damping damper apparatus of patent document 3 is described that the space | interval of a member can be changed in order to change a natural frequency, it is specified how a damper is comprised including a viscoelastic body. Not. Furthermore, the dynamic damper manufacturing method disclosed in Patent Document 4 describes that the outer pipe (casing) is changed in order to adjust the natural frequency. However, in a power generation engine or the like, the mounting location is limited. Therefore, it is not preferable that the external dimensions change (particularly, increase).
JP-A-5-187314 Japanese Utility Model Publication No. 6-4445 JP 2003-28237 A JP 2004-150544 A

  The present invention has been made to solve such a problem, and the object of the present invention is to check up and down as in the inspection platform or inspection platform provided in the diesel engine for rated operation. An object of the present invention is to provide a vertical dynamic damper that suppresses vibration of a vibrating structure.

In order to solve such problems, the invention according to claim 1 is a vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and is provided with a cylindrical case and the case. A guide bar, a vibration suppression weight slidably provided on the guide bar, coiled springs disposed on both sides of the vibration suppression weight, fitted to both ends of the case, and the guide bar In a vertical dynamic damper in which a damper main body is formed by a pair of guide bar supports that support the axial center portion of the case, a connecting portion is provided on the guide bar support fitted to the lower end of the case , and through the base portion attached to the connecting portion is erected the damper body on the inspection platform, and weight for the vibration suppression, the The measuring pins projecting radially dynamic suppression weights provided, further characterized in that a long hole that allows the reciprocating movement of the measuring pin into the flank of the case.

The invention according to claim 2 is a vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and includes a cylindrical case, a guide bar provided in the case, and a slide on the guide bar. A vibration suppression weight provided movably, coiled springs disposed on both sides of the vibration suppression weight, and fitted to both ends of the case, and the guide bar supported on the axial center of the case In a vertical dynamic damper in which a damper main body is formed by a pair of guide bar supports, the damper main body is a support frame constituting the inspection platform via a rib and a bracket provided on a side surface of the damper main body . It is characterized in that it is mounted vertically on a vertical member.

The invention according to claim 3, prior SL about the width of the frame constituting the inspection platform diameter of the damper body, to set the length of the damper body 5-6 times the diameter of the damper body Features.

  The invention according to claim 1 is a vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and includes a cylindrical case, a guide bar provided in the case, and a guide bar. A vibration suppressing weight provided slidably, coiled springs disposed on both sides of the vibration suppressing weight, fitted to both ends of the case, and the guide bar at the axial center of the case A damper main body is formed by a pair of supporting guide bar supports, and a connecting portion is provided on one of the guide bar supports, and the damper main body is placed on the inspection platform by a base portion attached to the connecting portion. When the inspection platform installed in the diesel engine for rated operation vibrates up and down, the vibration is applied to the damper Is transmitted to the vibration suppression weight, and the vibration suppression weight vibrates up and down. However, since there is a time difference between the vibration of the inspection platform and the vibration of the vibration suppression weight, the mutual vibrations are offset and The vertical vibration of the platform is suppressed. Moreover, this vertical dynamic damper can be easily and inexpensively manufactured because a cylindrical case is formed using a steel pipe for piping.

  In the invention according to claim 2, since the weight for adjusting the natural frequency is arranged between the guide bar support and the spring, the weight for adjusting the natural frequency is transferred to the position of the weight for suppressing the vibration. Even if the natural frequency is adjusted, the shape of the damper body remains unchanged. Therefore, each time the natural frequency of the damper is adjusted, it is not necessary to change the dimensions of the spring, so that the number of parts such as a spring can be reduced.

  In the invention according to claim 3, the vibration suppression weight is provided with a measuring pin protruding in the radial direction of the weight, and a long hole is provided on the lateral side of the case to allow the measuring pin to reciprocate. It is possible to visually check the operating state of the vibration suppression weight from the outside.

  According to a fourth aspect of the present invention, there is provided a vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and includes a cylindrical case, a guide bar provided in the case, and a guide bar. A vibration suppressing weight provided slidably, a coil-shaped spring disposed on both sides of the vibration suppressing weight, fitted to both ends of the case, and the guide bar at the axial center of the case A damper main body is formed by a pair of supporting guide bar supports, and a bracket is provided on a side surface of the damper main body via a rib, and the bracket and a vertical member of the support frame constituting the inspection platform are bolted Or by welding, if the frame constituting the inspection platform vibrates up and down together with the inspection platform, the vibration Is transmitted to the vibration suppression weight of the damper body, and the vibration suppression weight vibrates up and down, but between the vertical vibration of the support frame constituting the inspection platform and the vertical vibration of the vibration suppression weight. Since a time difference occurs, the mutual vibrations are canceled out, and vertical vibrations between the inspection platform and the support frame constituting the inspection platform are suppressed. Moreover, this vertical dynamic damper can be easily and inexpensively manufactured because a cylindrical case is formed using a steel pipe for piping.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1) Embodiment 1
In FIG. 1, reference numeral 100 denotes a large-sized low-speed two-cycle diesel engine for a power plant (for example, a rated rotational speed is 100 to 200 rpm, and an output number is about several thousand kW to 50,000 kW). An inspection platform 110 (not shown) is provided. In these inspection platforms 110, vertical dynamic dampers (hereinafter simply referred to as “dampers”) 1 are erected at locations where the vertical vibration is large, for example, at the ends of the inspection platform 110.

  As shown in FIG. 2, the damper 1 has a vertically long structure. The damper main body 10 has a cylindrical case 12, a guide bar 13 provided in the case 12, and a vibration slidably provided on the guide bar 13. A pair of restraining weights 14, coiled springs 15 and 16 disposed on both sides of the vibration restraining weight 14, and a pair that fits on both ends of the case 12 and supports the guide bar 13 on the axial center of the case 12. The guide bar supports 17 and 18 are formed. Then, the base portion 11 is screwed to a cylindrical connecting portion 19 provided on the lower guide bar support 18.

  The guide bar supports 17 and 18 are each formed in a cap shape and are fitted to the upper end and the lower end of the case 12. The guide bar support 18 fitted to the lower end of the case 12 has a cylindrical connecting portion 19 on its end surface. In addition, the base portion 11 is screwed to the female screw portion 20 provided on the inner peripheral surface of the cylindrical connecting portion 19. On the other hand, the base portion 11 is formed by a cylindrical portion 22 having a male screw portion 21 and a square substrate 23 (see FIG. 3) fixed to the cylindrical portion 22, and bolt holes 24 are provided at four corners of the substrate 23. ing.

  The guide bar 13 passes through a through hole 25 provided in the axial center portion of the upper and lower guide bar supports 17 and 18, and a tightening nut 27 is screwed into screw portions 26 provided at both ends thereof. Further, both ends of the coil springs 15 and 16 are supported by a pair of spring receivers 28, respectively. The spring receiver 28 has a convex shape in cross section, and has a through hole 29 in the axial center.

  The damper 1 constitutes a vibration system by a vibration suppression weight 14 and a pair of coil springs 15 and 16 provided above and below the weight. Further, the weight of the vibration system outside the system, that is, between the upper end guide bar support 17 and the uppermost spring receiver 28 and between the lower end guide bar support 18 and the lowermost spring receiver 28 is reduced. Several different types of natural frequency adjusting weights 30 and 31 are kept waiting.

  For example, a relatively light weight (for example, about 0.5 to 0.6 kg) between a plurality of (for example, two) natural frequency adjusting weights 30 is lighter than that (for example, 0.050 to 0.060 kg). A plurality of (for example, about five) natural frequency adjusting weights 31 are on standby. Although depending on the size of the damper, the weight of the vibration suppression weight 14 is, for example, about 1.9 to 2.0 kg, and the weight of the inner end spring receiver 28 is, for example, about 0.9 to 1.0 kg. It is.

  Further, the vibration suppression weight 14 is provided with a linear bush 33 that does not require oiling on the wall surface of the through hole 32 provided in the shaft center portion. Further, S and S ′ are assumed as vibration strokes of the vibration suppressing weight 14 and the inner end spring receiver 28.

  Further, in the damper 1, as shown in FIGS. 4 to 6, the vibration suppressing weight 14 is provided with a measuring pin 34 protruding in the radial direction, and the case 12 and a guide plate 35 provided on the case 12. Are provided with elongated holes 36 for protruding measuring pins. The measuring pin 34 includes a miniature bearing 37 at a position corresponding to the guide plate 35 so that the reciprocating motion is smooth. Reference numeral 38 designates a slide plate slidably provided on the guide plate 35 so as to follow the reciprocating motion of the measuring pin 34.

Here, when a vibration model is considered, the natural frequency f of the damper 1 can be expressed by the following equation.
That is,
f ∝ √ (K / M) = √ (k / m)
In addition,
M: Mass corresponding to the inspection platform K: Spring constant of the inspection platform m: Mass corresponding to the vibration system of the vertical dynamic damper k: Spring constant corresponding to the vibration system of the vertical dynamic damper.

  Therefore, according to the present invention, the natural frequency f of the damper can be easily changed by increasing or decreasing the weight of the weight constituting the vibration system of the damper. According to the present invention, since the weight of the vibration system is only increased or decreased, the dimensions of the damper itself are unchanged.

  As shown in FIG. 7, the weight of the vibration system weight is increased by using the natural frequency adjusting weights 30 and 31 waiting between the upper guide bar support 17 and the uppermost spring receiver 28 as shown in FIG. This is achieved by shifting to a position adjacent to the vibration suppression weight 14.

  On the other hand, weight reduction of the weight of the vibration system is achieved by placing the natural frequency adjusting weights 30 and / or 31 adjacent to the vibration suppressing weight 14 between the upper guide bar support 17 and the uppermost spring receiver 28. Alternatively, it is achieved by shifting between the lower guide bar support 18 and the lowermost spring receiver 28.

Next, the operation of the damper will be described.
As shown in FIG. 1, when the damper 1 is erected at the end of the inspection platform 110 provided in the upper and middle stages of the diesel engine 100, the diesel engine 100 operates and the inspection platform 110 vibrates up and down. The damper 1 erected at the end of the inspection platform 110 together with the inspection platform 110 vibrates up and down.

  When the damper 1 vibrates up and down, the vibration suppression weight 14 vibrates up and down via the upper and lower coil springs 17 and 18, but the vertical movement of the inspection platform 110 and the vertical movement of the vibration suppression weight 14 Since there is a time difference, the vertical vibration of the inspection platform 110 and the vertical vibration of the vibration suppression weight 14 are canceled out, and the vertical vibration of the inspection platform 110 provided in the diesel engine 100 is reduced.

  In the above description, the natural frequency adjusting weights 30 and 31 are provided between the upper spring 15 and the upper guide bar support 17 and between the lower spring 16 and the lower guide bar support 18. As described above, the natural frequency adjusting weights 30 and 31 are provided between the upper spring 15 and the upper guide bar support 17 or between the lower spring 16 and the lower guide bar support 18. Even if it arrange | positions in any one between, the same effect can be acquired.

(2) Embodiment 2
In the first embodiment, the case where the damper 1 is erected on the inspection platform 110 has been described. For example, as illustrated in FIG. 1, the damper main body 10 is supported by a support frame 120 that supports the inspection platform 110. The same effect can be expected even when attached to the side surface of the vertical member 121.

  That is, as shown in FIG. 8, the bracket 123 is provided on the side surface of the damper main body 10 via the rib 122, while the fixing is welded to the side surface of the vertical member 121 of the support frame 120 that supports the inspection platform 110. A support plate 125 is bolted to the plate 124, and the bracket 123 is fixed to the support plate 125 with bolts 126. For other structures, the same parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  The diameter of the damper main body 10 is set to about the width of the vertical member 121 of the support frame 120 constituting the inspection platform 110, and the length of the damper main body 10 is set to about 5 to 6 times the diameter of the damper main body 10.

It is a front view of the diesel engine which installed the dynamic damper concerning the present invention. It is a longitudinal cross-sectional view of the dynamic damper which concerns on this invention. It is a bottom view of the dynamic damper concerning the present invention. It is a principal part expanded sectional view of the dynamic damper which concerns on this invention. It is XX sectional drawing of FIG. It is an arrow view of the arrow Y direction of FIG. It is adjustment explanatory drawing of the fixed frequency of the dynamic damper which concerns on this invention. It is ZZ sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vertical dynamic damper 10 Damper main body 11 Base part 12 Case 13 Guide bar 14 Weight for vibration suppression 15,16 Spring 17,18 Guide bar support body 19 Connection part 100 Internal combustion engine 110 Inspection platform

Claims (3)

A vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and includes a cylindrical case, a guide bar provided in the case, and vibration suppression provided slidably on the guide bar. A weight, a coiled spring disposed on both sides of the vibration suppression weight, and a pair of guide bar supports that are fitted to both ends of the case and support the guide bar on the axial center portion of the case In the vertical dynamic damper formed with the damper main body, a connecting portion is provided on the guide bar support fitted to the lower end portion of the case, and the damper main body is used for the inspection via a base portion attached to the connecting portion. It is erected on the platform, and, in the vibration suppression weights to project in the radial direction of the weight for the vibration suppression Mejaringupi The provided, further, vertical dynamic damper characterized in that a long hole that allows the reciprocating movement of the measuring pin into the flank of the case. A vertical dynamic damper that suppresses vertical vibration of an inspection platform provided in an internal combustion engine, and includes a cylindrical case, a guide bar provided in the case, and vibration suppression provided slidably on the guide bar. A weight, a coiled spring disposed on both sides of the vibration suppression weight, and a pair of guide bar supports that are fitted to both ends of the case and support the guide bar on the axial center portion of the case In the vertical dynamic damper formed with the damper main body , the damper main body is vertically mounted on the vertical member of the support frame constituting the inspection platform via the rib and the bracket provided on the side surface of the damper main body . This is a vertical dynamic damper. The width of the longitudinal member of the support frame constituting the inspection platform diameter of the damper body, according to claim 2, wherein the setting the length of the damper body 5-6 times the diameter of the damper body Vertical dynamic damper.

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