JPH0768993B2 - Anti-vibration weighted bolt and its manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anti-vibration weighted bolt having a function of preventing resonance of a vibrating body and a method of manufacturing the same.

<Prior Art> When a vehicle is running or idling, vibration is generated in each member constituting the vehicle.

Each of these components has a unique frequency.

Therefore, when the vibration during traveling or the like coincides with the natural frequency of the constituent member, even if the vibration is small, it becomes a vibration (resonance phenomenon) with a very large amplitude, and the noise also increases.

Conventionally, a device called a dynamic damper or a mass damper has been adopted as a vibration and soundproof measure for a vehicle in such a case (see Japanese Utility Model Laid-Open No. 62-68051).

These dampers are weights for changing the natural frequency of each constituent member, and are attached to the vibrating portion of the constituent member of the vehicle to prevent resonance.

That is, by attaching the damper, the natural frequency of the constituent member is set outside the range of the frequency that is generated in the constituent member during traveling, etc., and the occurrence of resonance is prevented. Set the natural frequency to another value,
This is intended to attenuate resonance.

<Problems to be Solved by the Present Invention> Conventionally, when the damper as described above is mounted, the mounting space is limited, so that the damper is fixed to the vehicle body side with a screw or the like.

However, the portion of the constituent members of the vehicle that is the source of vibration is not the vehicle body, but the suspension, the transmission, the engine, or the frame in the vicinity thereof.

Therefore, in the conventional structure in which the damper is attached to the vehicle body, the damper is separated from the oscillation source, so that there is a problem that the vibration damping effect cannot be sufficiently obtained.

<Object of the present invention> The present invention has been made to solve the above problems, and an object of the present invention is to provide an anti-vibration weighted bolt that can obtain a sufficient anti-vibration effect and a manufacturing method thereof. And

<Means for Solving the Problems> That is, according to the present invention, a collar portion that receives an axial force by being pressed against a vibrating body is provided between the bolt head portion and the fastening screw portion, and the collar portion and the bolt head portion are provided. Between the and, a vibration-proof weight having a weight capable of changing the natural frequency of the vibrating body is attached,
Anti-vibration weighted bolt.

In the method for manufacturing the vibration-proof weighted bolt, a collar portion is formed in the direction orthogonal to the axis of the steel rod on the way of the steel rod having a threaded portion for fastening on one end side to fasten the steel rod. The side without screw threads is penetrated through the center of the vibration-proof weight with a certain weight, the penetrating end of the steel rod is forged, and the build-up part and bolt head are formed on one end surface of the vibration-proof weight. Then, the steel rod and the vibration-proof weight are integrally formed, which is a method for manufacturing a bolt with a vibration-proof weight.

<Operation of the Present Invention> The anti-vibration weight-equipped bolt of the present invention is used for assembling or installing a suspension, a transmission, or an engine, which is a source of vibration, or a frame or the like in the vicinity thereof.

By this, the natural frequency of each of the above-mentioned components of the vehicle is
It is possible to set the frequency outside the range of frequencies generated in the constituent members during running or idling so that the running frequency and the natural frequency do not match.

Therefore, the resonance of the constituent members can be prevented.

Further, the natural frequency of the constituent member can be set to another value to attenuate the resonance.

Even in the unlikely event that the antivibration weight falls off due to vibration, the antivibration weight and the fastening screw part are separated by the flange part, and the flange part and the fastening screw part remain without falling off. So it's safe.

<Example> Hereinafter, an example of the present invention is described in detail based on a drawing.

<a> Bolt structure (Fig. 1) The bolt 1 is configured such that the bolt head 14 and the fastening screw portion 12 are
A flange 11 is provided that receives axial force by pressing against the vibrating body.
The vibration-proof weight 2 is attached between the 11 and the bolt head 14.

The collar portion 11 is a plate body provided in a direction orthogonal to the axis of the bolt 1.

The vibration-proof weight 2 has a weight that can change the natural frequency of the vibrating body.

For example, a predetermined weight is applied to the antivibration weight 2 so that the natural frequency of the components of the vehicle can be set outside the range of the frequencies generated in the components during running or idling.

Further, the collar portion 11 and the antivibration weight 2 are formed in contact with each other to prevent the antivibration weight 2 from being lost and prevent the fastening function of the bolt from being deteriorated.

The bolt head 14 is formed in a cross-sectional shape such as a hexagon and has a function for fastening the bolt 1.

<B> Manufacturing Method The anti-vibration weighted bolt 1 of this embodiment can be manufactured by the following method.

(1) Manufacturing method by caulking the head (Figs. 1 to 5) As shown in Fig. 2, the bolt 1 has a collar portion 11 formed on the steel rod in the direction orthogonal to the axis of the steel rod. Further, a fastening screw portion 12 is formed on one end side of the steel rod.

The end of the steel rod opposite to the fastening screw part 12 is caulked part 13
And

The collar portion 11, the fastening screw portion 12, and the crimp portion 13 are integrally formed in advance by die forging or the like by cold working.

On the other hand, a through hole 21 slightly larger than the diameter of the caulking portion 13 is formed in the center portion of the vibration-proof weight 2.

Next, as shown in FIGS.
Penetrate 13

As shown in FIG. 3, a through hole is formed at the center of the antivibration weight 2.
There is also a case where a cylindrical inner collar 23 having 22 is positioned and an elastic member 24 such as rubber or spring is arranged between the inner collar 23 and the vibration-proof weight 2.

Next, the through portion of the caulked portion 13 is caulked by die forging or the like by cold working to form the bolt head 14.

When the bolt head 14 is formed, the peripheral portion of the caulking portion 13 is forged with an internal press material smaller than the diameter of the caulking portion 13 to form the built-up portion 15 on the end surface of the vibration-proof weight 2.

Thereby, the vibration-proof weight 2 and the steel rod can be integrated.

Further, the bolt head 14 is forged into a hexagonal shape or the like so that the bolt 1 can be fastened.

(2) Manufacturing method by head welding (Figs. 6 and 7) As shown in Fig. 6, a fastening screw portion of the collar portion 11 of the bolt 1
A mounting steel rod (16) is provided coaxially with the fastening screw portion (12) on the end face on the side opposite to (12).

A threaded portion 17 is formed on the mounting steel rod 16.

The through hole 25 of the antivibration weight 2 is opened slightly smaller than the diameter of the mounting steel rod 16, and the mounting steel rod 16 is press-fitted into the through hole 25 so as to penetrate therethrough.

Then, attach the nut 3 to the threaded portion 17 of the mounting steel rod 16,
The nut 3 and the mounting steel rod 16 are integrated by welding (welding portion 31).

(3) Manufacturing method by swaging the collar (Figs. 8 and 9) As another method, as shown in Fig. 8, the bolt head
The bolt 4 is formed from the caulking portion 41 of the steel rod body 41 and the fastening screw portion 43 having a diameter smaller than that of the caulking portion 42.

Then, the caulking portion 42 is press-fitted into the through hole 21 of the vibration-proof weight 2 from the fastening screw portion 43 side so as to penetrate therethrough.

Next, the penetrating end of the crimped portion 42 is crimped by die forging or the like by cold working to integrate the vibration-proof weight 2 and the bolt 4 and form the collar portion 44.

Although the method for manufacturing the anti-vibration weighted bolt 1 has been described above, various other manufacturing methods are possible.

<Experimental Results> For example, as shown in FIG. 10, the anti-vibration weight bolts 1 are attached to the mounting bolts at both ends of the suspension arm 5 (connecting the tire 51 and the front axle body 52) near the source of vibration. use.

Then, the vibration and noise at the time of running and idling of the vehicle were measured.

Then, the experimental results shown in FIGS. 11 and 12 were obtained.

From this experimental result, it can be seen that both vibration and noise are high when the anti-vibration weight bolt 1 is not attached, but both vibration and noise are reduced when the anti-vibration weight bolt 1 is attached.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> The conventional structure in which the dynamic damper or the mass damper is attached to the vehicle body has a problem that the vibration isolation effect cannot be sufficiently obtained because these dampers are separated from the oscillation source.

On the other hand, according to the present invention, a vibration damping weight is integrally formed on a bolt used for assembling or installing a suspension, a transmission device or an engine which is a source of vibration, or a frame or the like in the vicinity thereof.

Therefore, according to the present invention, the anti-vibration weight can be attached not to the vehicle body but to the vicinity of the vibration source, so that the resonance of the constituent members of the vehicle can be prevented more effectively and the vibration and the noise can be reduced than the conventional case. it can.

<B> Conventionally, a dedicated space for installing a dynamic damper or mass damper is secured on the vehicle body,
These dampers were fixed to the car body with screws.

On the other hand, the present invention does not require a dedicated space for mounting because it has a structure in which the bolts used for assembling the components of the vehicle and the like are integrated with the antivibration weight.

Also, at the same time as the assembly work and installation work of the components of the vehicle,
Anti-vibration weights can be attached.

Therefore, the manufacturing cost can be reduced and the mounting work can be simplified.

<C> Since the anti-vibration weight of the present invention is integrated with the bolt as described above, it does not require a dedicated mounting space and can be easily attached and detached.

Therefore, it can be installed at any position of the vehicle, and can be installed at a place where a vibration-proof weight needs to be installed, and the vibration-proof and sound-proof effects can be improved.

<D> The present invention makes it possible to select the most suitable anti-vibration weight bolt for engine powertrain specifications and suspension specifications when assembling a vehicle. Can be managed.

<E> The vibration-proof weight and the screw portion for fastening the bolt are separated by the flange portion.

Therefore, even in the unlikely event that the antivibration weight falls off due to vibration, the collar portion and the fastening screw portion remain without dropping off.

Therefore, safety is ensured without losing the fastening function between the constituent members of the vehicle.

<F> The anti-vibration weighted bolt of the present invention is not limited to a vehicle, and can be attached to a vibrating portion of other machines, instruments, devices, etc. to prevent resonance and provide vibration-proof and sound-proof effects.

<G> In the case of a manufacturing method in which the crimped part of the steel rod is passed through the antivibration weight and the penetrating end is forged to integrate the antivibration weight and the steel rod, all the steps of bolt production are cold worked. Since it can be formed by forging, the manufacturing cost is low.

[Brief description of drawings]

 Fig. 1: Perspective view of bolt of the present invention Fig. 2-5: Explanatory diagram of bolt manufacturing method Fig. 6-9: Explanatory diagram of other manufacturing method Fig. 10: Explanatory diagram of application example 11, 12 Figure: Graph showing experimental results

Claims (2)

[Claims] 1. A flange part is provided between the bolt head and the fastening screw part to receive an axial force by pressing against the vibrating body, and the flange part is in contact with the flange part between the flange part and the bolt head. An anti-vibration weight bolt, characterized in that an anti-vibration weight having a weight capable of changing the natural frequency of the vibrating body is attached to the anti-vibration weight. 2. A steel rod having a fastening screw portion on one end side is formed with a collar portion in a direction orthogonal to the axis of the steel rod, and the side of the steel rod having no fastening screw portion is It penetrates through the center of the anti-vibration weight having a specified weight, the forged end of the steel rod is forged, and the built-up part and the bolt head are formed on one end surface of the anti-vibration weight, and the steel rod and anti-vibration A method for manufacturing an anti-vibration bolt with a weight, characterized in that the weight is integrally formed.