JPH1113940A - Supporting device for fluid piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an exciting force under the intrinsic vibration number of a structure having fluid piping and to prevent noises produced by the resonance of the structure by clamping the fluid piping on the structure in the node position of the vibration mode of the fluid piping excited by fluid pressure pulsation. SOLUTION: A plurality of attaching seats 2 are fixed to the upper surface of a construction machine 1, a recessed part 21 and a screw hole 22 are provided in each attaching seat 2 and vibration preventive rubber 3 is provided over the recessed part 21. A notched part 31 is provided in the upper part of the vibration preventive rubber 3, and two hydraulic piping lines 4A and 4B are provided thereon and fixed by a bolt 6 by using a fastening tool 5 having a notched part 51. In this case, the position of a clamp between the hydraulic piping lines 4A and 4B is selected from a plurality of pre-installed boom attaching seats 2, and the position selected is decided to be a position contacted with the node of the hydraulic piping lines 4A and 4B. Thus, the vibration of a boom 1 is reduced, and noises produced by resonance between the hydraulic piping lines 4A and 4B and the boom 1 are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pipe support device fixed to a boom or the like of a construction machine.

[0002]

2. Description of the Related Art FIG. 7 shows an external view of a hydraulic shovel. In such a hydraulic excavator, the hydraulic cylinder C1,
The boom BM, arm AM, and bucket BK are driven by the expansion and contraction of C2 and C3. The hydraulic piping for supplying the hydraulic pressure to the hydraulic cylinders C2 and C3 is located at several positions (a, (b, c) is clamped to the boom BM. The hydraulic piping vibrates at a frequency f represented by the following equation, with the pulsation of the pump serving as a vibration source. f = (N / 60) × n (Hz) where N: engine speed n: number of pistons of hydraulic pump Therefore, the hydraulic piping and the boom attenuate the vibration of the hydraulic piping and reduce the excitation source to the boom It is clamped through the anti-vibration rubber for the purpose of.

[0003]

However, since the clamping force of the clamp is generally high, it is not possible to obtain a sufficient damping effect even if the pipe is clamped via the vibration-proof rubber, and the vibration-proof measures are insufficient. Remains. Also, regarding the clamp position of the hydraulic pipe, no special consideration is usually given to reduce the vibration, and much less the vibration mode of the hydraulic pipe.

[0004] The vibration characteristics of the hydraulic pipe at the clamp position change in accordance with the frequency f, and the vibration serves as an excitation source to vibrate the boom. Therefore, when the hydraulic pipe is vibrating at a frequency equal to its natural frequency f1, the excitation source for the boom is at a maximum when the clamp position is at the antinode position of the vibration mode of the hydraulic pipe, that is, at a position where the amplitude of the clamp is large. Further, if the frequency f1 is equal to the natural frequency of the boom, the boom resonates greatly, and as a result, a problem such as generation of a resonance sound occurs. This phenomenon will be described below based on test results and analysis results.

FIG. 9 shows a hydraulic pipe clamp b (FIG. 8) which is attached to a boom by a regular supporting method, applies a load to a hydraulic pump under normal hydraulic relief conditions, and generates hydraulic pulsation at that time. This is a result of actually measuring vibration data, in which the horizontal axis represents frequency and the vertical axis represents amplitude.
In FIG. 9, the amplitude is maximum at the frequency f1,
This frequency f1 corresponds to the natural frequency of the hydraulic piping. FIG. 10 shows the vibration mode of the hydraulic pipe alone corresponding to the frequency f1 obtained by the experimental modal analysis. The horizontal axis indicates the vibration mode measurement position of the hydraulic pipe, and the vertical axis indicates the amplitude.
FIG. 11 is an FE showing the vibration mode of the hydraulic pipe at the frequency f1 when the hydraulic pipe is clamped at a, b, and c in FIG.
It is an M analysis result, in which the horizontal axis indicates the vibration mode calculation position of the hydraulic piping and the vertical axis indicates the amplitude. In FIG. 11, the amplitude of the clamp b is much larger than the amplitudes of the clamps a and c, and the position of the clamp b is exactly the antinode of the vibration of the hydraulic piping.

FIG. 12 shows vibration data measured at the d portion of the antinode of the boom BM shown in FIG. 13 when vibration occurs in the hydraulic piping under the same conditions as in FIG. The amplitude is shown. In FIG. 12, the amplitude is maximum at the frequency f1, and this frequency f1 corresponds to the natural frequency of the boom and coincides with the natural frequency of the hydraulic piping. FIG. 14 shows an amplitude distribution around the measurement unit d at the frequency f1. As shown in FIG. 14, the d portion of the antinode of the boom BM vibrates greatly at the frequency f1.

As described above, when the hydraulic piping is clamped at the position of the antinode of the specific frequency f, the boom receives a large excitation source from the hydraulic piping, and the vibration of the boom increases. In particular, when vibrating at the frequency f1, which is the natural frequency of the hydraulic pipe and the boom, the hydraulic pipe and the boom resonate, and the antinode position b in the vibration mode of the hydraulic pipe b
When the hydraulic piping is clamped, the resonance energy of the vibration becomes excessive, and as a result, the boom resonates and causes noise.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluid pipe supporting device which reduces the number of excitation sources of a structure having a fluid pipe under a natural frequency and prevents noise due to resonance of the structure. .

[0009]

[Means for Solving the Problems]

(1) Referring to FIGS. 1 and 2 showing an embodiment, the invention of claim 1 is applied to a fluid pipe support device installed in a structure 1 and is excited by fluid pressure pulsation. At the nodes of the vibration modes of the fluid pipes 4A and 4B
The above object is achieved by clamping the fluid pipes 4A and 4B to the structure 1. (2) The invention of claim 2 is applied to a support device for the fluid pipes 4A, 4B arranged on the structure 1 by a three-point clamp, and a plurality of intermediate point clamp positions are provided between the clamp positions L1, L6 at both ends. The above object is achieved by setting L2 to L5 and clamping the fluid pipes 4A and 4B at the intermediate point clamping position L4 closest to the node of the vibration mode.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a layout view of clamps arranged on a boom, and clamps a, b ′, and c are clamps a and b in FIG. 8, respectively.
b 'and c. FIG. 2 shows the clamps a,
It is sectional drawing of the clamp of b 'and c. In FIG. 2, a mounting seat 2 is fixed to an upper surface of a boom 1. As shown in FIG. 1, a plurality of mounting seats 2 are provided at positions L1 to L6 on the boom, and clamps a,
c is installed. The position of the clamp b 'is L2-L5
Is determined by the method described later.

The mounting seat 2 is provided with a concave portion 21 and a screw hole 22, respectively, and the anti-vibration rubber 3 is installed on the concave portion 21. A notch 31 is provided on the upper part of the vibration isolating rubber 3, and two hydraulic pipes 4 </ b> A,
4B is installed. A fastener 5 having a notch 51 is provided on the hydraulic pipes 4A and 4B, and a through hole 52 is opened in the fastener 5. Bolt 6
The hydraulic pipes 4A and 4B are clamped through the through holes 52 and screwed into the screw holes 22 of the mounting seat 2. As described above, according to the first embodiment, a plurality of mounting seats 2 are provided at the positions L1 to L6, and the position of the clamp b 'can be selected from the positions L2 to L5. The position of the clamp b 'is determined by the following procedure.

First, the vibration mode of a single hydraulic pipe at a specific frequency f is grasped. The specific frequency f is a frequency corresponding to the natural frequency f1 of the hydraulic pipes 4a and 4b where vibration is particularly problematic. FIG. 10 shows the vibration mode of the hydraulic pipe alone determined by the experimental modal analysis as described above. The experimental modal analysis is performed by filling a hydraulic pipe supported at both ends free with hydraulic oil of a predetermined pressure and using a hammering method. Based on the experimental results shown in FIG. 10, the position where the amplitude is the smallest is specified from among the amplitudes corresponding to the positions L2 to L5. Then, the clamp b 'of the hydraulic pipe is set at the position L4.

FIG. 3 is a FEM analysis result showing the vibration mode of the hydraulic pipe when the clamp b 'is set at the position L4 in FIG. 1, in which the horizontal axis indicates the clamp position and the vertical axis indicates the amplitude. Comparing with the amplitude of the clamp b shown in FIG.
The amplitude of the clamp b 'is reduced to less than half. FIG.
Is the boom B when clamped by the clamps a, b 'and c
It is the actually measured vibration data near the d part of the antinode of M, and shows the amplitude of the surface of the antinode of the boom. As shown in FIG. 4, the vibration of the boom d is greatly reduced as compared with the vibration data of the boom d when clamped by the clamps a, b, and c shown in FIG. This is because the amplitude of the clamp b ', which is the excitation source of the boom, is greatly reduced as compared with the amplitude of the clamp b.

As described above, according to the first embodiment, the position of the intermediate clamp b 'of the hydraulic pipe is selected from a plurality of boom mounting seats 2 provided in advance. Since the clamp is performed at the position of the node of the vibration mode, the excitation source for the boom can be reduced. As a result, vibration of the boom can be reduced, and noise due to resonance between the hydraulic piping and the boom can be prevented.

Second Embodiment FIG. 5 is a layout view of clamps arranged on a boom according to a second embodiment, and clamps a, b ″, and c are each a clamp a in FIG. , b ″, c. FIG.
FIG. 6 is a cross-sectional view of the clamp at a position b ″ in FIG. 5.
The same parts as those in FIGS. 1 and 2 of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. 5 and 6, the mounting seat 200 has a slot hole 201 having a length LA.
Is open. Further, a circular hole 32 and a circular hole 53 are opened at the center of the vibration isolating rubber 3 and the fastening tool 50. The head of the bolt 7 is the widened portion 201 of the slot hole 201.
a, the lower part of the neck penetrates through the slot hole 201, the circular hole 32, and the circular hole 53 and is fastened by the nut 8, thereby clamping the hydraulic pipes 4A and 4B. By sliding the head of the bolt 7 in the slot hole 201, the clamp b ″
Can be changed freely within the range of the length LA.

The setting of the position of the clamp b "is performed in the same procedure as described in the first embodiment, and the position is determined at a position where the amplitude of the vibration mode of the hydraulic pipe alone becomes minimum. .

As described above, according to the second embodiment, since the slot hole 201 is provided in the mounting seat 200, the position of the clamp b "is set arbitrarily within the range of the length LA of the slot hole. As a result, the position of the clamp b ″ can be adjusted arbitrarily, and the hydraulic pipe can be clamped to a position where the amplitude of the vibration mode of the hydraulic pipe alone becomes the minimum, so that the vibration level of the boom can be reduced. Can be minimized.

Although the piping support device in the above embodiment is applied to the hydraulic piping of a boom of a hydraulic shovel, the invention is not limited to this, and is similarly applied to another structure having a fluid piping support device. The present invention can be similarly applied to, for example, pneumatic piping other than hydraulic piping. Although the number of clamps is three and the number of pipes is two, the invention is not limited to these.

[0020]

As described above in detail, according to the first aspect of the present invention, since the clamp is performed at the node of the vibration mode of the hydraulic pipe, the excitation source to the structure such as the boom is reduced. As a result, vibration of the structure itself can be reduced, and noise due to resonance between the hydraulic piping and the structure can be prevented. According to the second aspect of the present invention, in the hydraulic piping support device arranged by the three-point clamp, a plurality of mounting seats or slot holes are provided, so that the position of the intermediate clamp can be set to the antinode of the vibration mode of the hydraulic piping. The position can be easily changed.

[Brief description of the drawings]

FIG. 1 is an arrangement diagram of a clamp according to a first embodiment.

FIG. 2 is a cross-sectional view of the clamp according to the first embodiment.

FIG. 3 is a graph showing an FEM analysis result of the hydraulic piping according to the first embodiment.

FIG. 4 is a graph showing vibration distribution data of the boom according to the first embodiment.

FIG. 5 is an arrangement diagram of a clamp according to the second embodiment.

FIG. 6 is a sectional view of a clamp according to the second embodiment.

FIG. 7 is an external view of a hydraulic excavator.

FIG. 8 is a hydraulic piping layout diagram of the hydraulic shovel.

FIG. 9 is a graph showing vibration data of a hydraulic pipe according to a conventional technique.

FIG. 10 is a graph showing an experimental modal analysis result of a single hydraulic pipe.

FIG. 11 is a graph showing a result of FEM analysis of a hydraulic pipe according to the related art.

FIG. 12 is a graph showing vibration data of a boom according to the related art.

FIG. 13 is a perspective view illustrating the abdomen of the boom.

FIG. 14 is a graph showing vibration distribution data of a boom according to the related art.

[Explanation of symbols]

 1 Boom 4A, 4B Hydraulic piping L1, L6 Both ends clamp position L2-L5 Intermediate clamp position

Claims (2)

[Claims] 1. A device for supporting a fluid pipe installed in a structure, wherein the fluid pipe is clamped to the structure at a node of a vibration mode of the fluid pipe excited by fluid pressure pulsation. A fluid pipe support device characterized by the above-mentioned. 2. A fluid pipe support device disposed on a structure by a three-point clamp, wherein a plurality of intermediate point clamp positions are set between clamp positions at both ends, and the intermediate point clamp closest to a node of the vibration mode. A fluid piping support device, wherein the fluid piping is clamped at a position.