JP6937506B2 - Vibration shaft for concrete internal vibrator - Google Patents

Description

The present invention relates to a vibration shaft for a concrete internal vibrator, which is a vibration source of a concrete internal vibrator that compacts concrete by inserting a rod-shaped vibrating body into concrete to be placed and applying vibration. ..

The vibrating shaft for a concrete internal vibrator (hereinafter referred to as "vibration shaft") is rotatably attached to the inside of a rod-shaped vibrating body provided in the concrete internal vibrating body, and generates vibration in the vibrating body by rotating. Therefore, it functions as a vibration source of the concrete internal vibrator.

In order to generate vibration in the vibrating body by the rotation of the vibrating shaft, it is necessary to deviate (eccentricize) the center of gravity of the vibrating shaft from the rotating shaft of the vibrating shaft. In general, a body having a substantially semicircular cross section is provided with rotating shafts at both upper ends.
Such a vibration shaft is usually formed by cutting the body of a columnar rod-shaped member having rotation shafts formed at both ends into a substantially semicircular cross section. That is, in the conventional vibrating shaft, in order to eccentric the vibrating shaft while allowing the rotating shaft of the vibrating shaft to be fixed to the bearing of the vibrating body, the body of the vibrating body must be cut into a semicircular cross section. There is no choice but to make it a shape.

By the way, when the body of a vibrating shaft having rotating shafts at both ends is formed into a substantially semicircular cross section by cutting, the rod-shaped member is inevitably deformed so as to project in the arc direction having a substantially semicircular cross section during cutting. Therefore, it is necessary to correct this deformation. Further, since this correction work requires skill, there is a problem that not only the production efficiency is poor but also the quality varies.

In addition, since the body of the vibrating shaft is formed in a semicircular cross section, when it is mounted inside the vibrating body and rotated at high speed, the centrifugal force causes the deflection in the arc direction of the semicircular cross section during rotation. There is also a problem that a rope jumping phenomenon occurs), which adversely affects the bearing of the attached vibrating body. In particular, when the vibration axis is long, such deflection is likely to occur.

Jikkenhei 7-29199 Japanese Unexamined Patent Publication No. 10-292628

An object of the present invention is to obtain a vibrating shaft for a concrete internal vibrator that eccentricizes the vibrating shaft without cutting and is less likely to bend even at high speed rotation.

The vibration shaft for a concrete vibrator of the present invention is rotatably stopped inside the vibrating body of a concrete internal vibrating body provided with a rod-shaped vibrating body, and the vibration for the concrete internal vibrator generates vibration in the vibrating body by rotation. An arc centered on a straight line that divides the angle between the two sides less than 180 degrees by drawing or extrusion, and forms an outer arc. It is composed of a rod-shaped member formed in a substantially fan-shaped cross section, and is configured by providing rotation axes centered on the center of the arc at both ends of the rod-shaped member in the longitudinal direction.

The rod-shaped member may be formed into a substantially fan-shaped cross section having a central angle of less than 180 degrees by drawing or extrusion, that is, the rod-shaped member may be formed so that the central side of the substantially fan shape is convex, and the material may be drawn. Alternatively, it is conceivable to use a metal rod-shaped member such as iron or copper that can be easily extruded.

In the invention of claim 2, the portion where the two sides of the substantially fan-shaped cross section intersect is formed in an arc shape, and the base end of the rotating shaft is a bearing contact formed by a step portion whose diameter is expanded concentrically with the rotating shaft. It is characterized in that a portion is provided so that a part of the outer circumference of the bearing contact portion is continuous with the arc of the portion where the two sides of the substantially fan-shaped cross section intersect.

The invention of claim 3 is characterized in that the outer arc having a substantially fan-shaped cross section is formed into a semicircular arc.

According to the present invention, the angle formed by two sides by drawing or extrusion is less than 180 degrees, and an arc centered on a straight line that equally divides the angle formed by the two sides forms an outer arc. Since the rotating shafts centered on the center of the arc are provided at both ends of the rod-shaped member formed in a substantially fan-shaped cross section in the longitudinal direction, the vibrating shaft can be eccentric without cutting, and the inside of the vibrating body can be eccentric. It is possible to obtain a vibrating shaft for a concrete internal sector that is less likely to bend even when mounted on a machine and rotated at high speed.
That is, since the vibration shaft is formed by using a rod-shaped member having a substantially fan-shaped cross section by drawing or extrusion, the body of the rod-shaped member is cut into a semicircular shape like a conventional vibration shaft. No need. And, instead of a semicircular cross section, the side where the two sides of the substantially fan shape intersect is formed in a substantially fan shape with a convex cross section, so the side where the two sides of the convex shape intersect has a function like a reinforcing rib. As a result, the occurrence of deflection can be suppressed.
Further, since the axial centers of the rotating shafts provided at both ends of the rod-shaped member having a substantially fan-shaped cross section coincide with the center of the arc forming the outer arc having a substantially fan-shaped cross section, the cross section when the vibration axis is rotated. The rotational trajectory of the substantially fan-shaped outer arc coincides with the arc that forms this outer arc. Therefore, the radius of gyration of the vibrating shaft can be minimized, and the diameter of the rod-shaped vibrating body to which the vibrating shaft is mounted can be minimized.

According to the invention of claim 2, a portion where two sides having a substantially fan-shaped cross section intersect is formed in an arc shape, and a bearing contact consisting of a step portion whose diameter is concentrically expanded from the rotating shaft at the base end of the rotating shaft. Since a portion is provided so that a part of the outer periphery of the bearing contact portion is continuous with the arc of the portion where the two sides of the substantially fan-shaped cross section intersect, the outer arc of the substantially fan-shaped cross section is sandwiched between the axes of the rotating shaft. The weight generated on the opposite side (the weight on the non-eccentric side of a bar-shaped member having a substantially fan-shaped cross section) can be minimized to minimize the cancellation of the degree of eccentricity of the vibration axis, which is generated by rotation. The damping of vibrations that can be made can be reduced as much as possible.

According to the invention of claim 3, since the outer arc having a substantially fan-shaped cross section is a semicircular arc, the weight on the eccentric side of the rod-shaped member having a substantially fan-shaped cross section can be maximized, thereby rotating. The vibration that sometimes occurs can be made as large as possible.

Perspective view showing the outline of this invention Also front view Side view as well Similarly, a central cross-sectional view The figure which shows the rotation trajectory of the vibration axis of this invention The figure which shows the state which attached the vibrating shaft of this invention to the vibrating body of the concrete internal vibrating machine. Diagram showing the conventional vibration axis (strabismus view and central cross-sectional view)

1 to 4 are views showing an outline of an embodiment of the present invention, FIG. 1 is a perspective view, FIG. 2 is a front view, FIG. 3 is a side view, and FIG. 4 is a central cross-sectional view.

The vibrating shaft 1 for a concrete internal vibrator is composed of an iron rod-shaped member 2 formed in a substantially fan-shaped cross section by drawing or extrusion.
The angle θ formed by the two sides forming the substantially fan-shaped cross section of the rod-shaped member 2 is approximately 116 degrees, and the semicircular arc centered on the point O on the straight line that equally divides this angle is outside the substantially fan-shaped cross section. It constitutes an arc L.
Further, a portion where two sides having a substantially fan-shaped cross section intersect is also formed in an arc shape.

Rotating shafts 3 having a circular cross section are provided at both ends of the rod-shaped member 2 in the longitudinal direction with a point O, which is the center of the arc forming the outer arc L having a substantially fan-shaped cross section, as an axis, and the base of the rotating shaft 3 is provided. At the end, a bearing contact portion 31 composed of a step portion whose diameter is expanded concentrically with the rotating shaft 3 is provided. Further, a part of the outer circumference 31a of the bearing contact portion 31 is formed so as to be continuous with the arc of the portion where the two sides having a substantially fan-shaped cross section intersect.
By inserting the rotating shaft 3 into the bearing of the rod-shaped vibrating body of the concrete internal vibrator, the vibrating shaft 1 is rotatably stopped inside the vibrating body.

As described above, since the vibrating shaft 1 uses the rod-shaped member 2 formed in a substantially fan-shaped cross section by drawing or extrusion, the body of the rod-shaped member 2 is purposely cut in order to eccentric the vibrating shaft 1. There is no need for it, and there is no possibility that deformation will occur in the outer arc L direction during processing. Further, the vibrating body 1 is formed so that the intersecting portion side of the two sides having a substantially fan-shaped cross section is convex, and this portion side is reinforced, so that the vibrating body 1 is generated when the vibrating shaft has a semicircular cross section. It is possible to suppress the occurrence of such "deflection".

FIG. 5 is a schematic diagram for explaining a rotation trajectory when the vibration shaft 1 is rotated inside the vibrating body of the concrete internal vibrator.
Since the rotating shaft 3 has a point O, which is the center of the arc forming the outer arc L of the vibrating body 1, as the axis, when the vibrating shaft 1 is rotated around the rotating shaft 3, the outer arc L of the vibrating shaft 1 is rotated. Rotates with an arc R centered on the point O as a rotation trajectory. Therefore, the radius of gyration of the vibrating shaft 1 can be minimized, and the diameter of the rod-shaped vibrating body of the concrete internal vibrator to which the vibrating shaft 1 is mounted can be minimized.

This embodiment shows an example of a vibrating shaft that can maximize the vibration generated in the vibrating body when the vibrating shaft is mounted inside a vibrating body having a predetermined size. Therefore, the angle θ formed by the two sides can be appropriately selected in the range of less than 180 degrees depending on the vibration generated in the vibrating body.

FIG. 6 is a diagram showing an outline of a state in which the vibrating shaft 1 for a concrete internal vibrator is attached to the inside of a rod-shaped vibrating body of a concrete internal vibrator.
The rod-shaped vibrating body 4 of the concrete internal vibrator is configured to have a hollow tubular shape, and inside the rod-shaped vibrating body 4, the vibrating shaft 1 is a rotating shaft 3 provided in the longitudinal direction of the vibrating shaft 1. 3 is inserted into the bearings 5 and 5 so that the bearing contact portions 31 and 31 provided at the base ends of the rotating shafts 3 and 3 abut on the bearings (ball bearings) 5 and 5, respectively, thereby causing rod-shaped vibration. It is rotatably fixed inside the body 4.
The diameter of the internal space of the rod-shaped vibrating body 4 is slightly smaller than the diameter of the rotating orbit R drawn by the outer arc of the vibrating body 1 when the vibrating shaft 1 having a substantially fan-shaped cross section rotates around the axis O of the rotating shaft 3. It has a large diameter and is the minimum diameter of the internal space required for the rotation of the vibration shaft 1.

A nut 6 is attached to the tip of the rotating shaft 3 inserted into the bearing 5 on the tip side of the vibrating body 4 so that the rotating shaft 3 cannot be pulled out from the bearing 5. On the other hand, a joint shaft 7 is attached to the tip of the rotating shaft 3 inserted into the bearing 5 on the base end side of the vibrating body 4, and the joint shaft 7 is further connected to the flexible shaft 8. The flexible shaft 8 is connected to an output shaft of a motor (not shown), and has a function of transmitting the rotational force of the motor to the vibration shaft 1.
Reference numeral 9 in the drawing is a hose for protecting the flexible shaft 8, and reference numeral 10 is a joint for connecting the vibrating body 4 and the hose 9.

When the motor of the concrete internal vibrator is rotated, the rotational force is transmitted from the output shaft of the motor to the flexible shaft 8 and transmitted to the vibration shaft 1 via the joint shaft 7, so that the vibration shaft 1 moves inside the vibrating body 4. It rotates around the axis O of the rotating shaft 3. Since the vibration shaft 1 is formed in a substantially fan-shaped cross section and is eccentric, the vibrating body 4 vibrates due to its rotation.

The present invention relates to a vibration shaft for a concrete internal vibrator, which is a vibration source of a concrete internal vibrator that compacts concrete by inserting a rod-shaped vibrating body into concrete to be placed and applying vibration. , Has industrial availability.

1 Vibration shaft for concrete internal vibrator 2 Rod-shaped member 3 Rotating shaft 31 Bearing contact part O Center of outer arc L Outer arc θ Angle between two sides R Rotating track 4 Vibrating body 5 Bearing (ball bearing)
6 Nut 7 Joint Shaft 8 Flexible Shaft 9 Hose 10 Joint

Claims (3)

A vibrating shaft for a concrete internal vibrator provided with a rod-shaped vibrating body, which is rotatably fixed inside the vibrating body and generates vibration in the vibrating body by rotation.
By drawing or extrusion, the angle between the two sides is less than 180 degrees, and the arc centered on one point on the straight line that divides the angle between the two sides is formed into a fan shape with an outer arc. It consists of a rod-like member,
Rotating axes centered on the center of the arc are provided at both ends of the rod-shaped member in the longitudinal direction.
Vibration shaft for concrete internal vibrator.
The part where the two sides of the fan-shaped cross section intersect is formed in an arc shape.
At the base end of the rotating shaft, a bearing contact portion having a stepped portion whose diameter is expanded concentrically with the rotating shaft is provided.
A part of the outer circumference of the bearing contact portion is made continuous with the arc of the portion where the two sides of the substantially fan-shaped cross section intersect.
The vibrating shaft for a concrete internal vibrator according to claim 1. The outer arc with a substantially fan-shaped cross section is a semicircular arc.
The vibrating shaft for a concrete internal vibrator according to claim 1 or 2.

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