JPS5810749Y2 - Rammer impact amplitude adjustment mechanism - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a striking amplitude adjustment mechanism for a rammer.

In civil engineering work, rammers are widely used as devices that compact the ground by applying impact force to it.

A rammer generally uses a crank mechanism to convert the rotational force of a prime mover into vertical motion, which causes a lower ramming shoe to vibrate up and down, thereby impacting the ground and compacting it.

Incidentally, the sites where rammers are used for compaction range from soft soils such as sandy soils to hard soils such as asphalt mixtures. It is necessary to adjust the striking force, that is, the striking amplitude accordingly.

In order to adjust the impact force, conventional rammers employ a mechanism in which a speed regulating lever is provided on the operating handle, and this speed regulating lever adjusts the impact amplitude by changing the rotational speed of the prime mover.

However, such adjustment of the impact amplitude by the rotational speed of the prime mover has an extremely narrow adjustment range.
For this reason, it is not possible to obtain a wide range of impact amplitudes corresponding to a wide variety of soil types.

In addition, for this reason, a structure has been proposed in which the amplitude of the ramming shoe is adjusted by changing the mounting position of the crank rod with respect to the crank that constitutes the crank mechanism, but the adjustment operation is difficult. At present, it is complicated and has not yet been put into practical use.

The present invention has been devised in view of the above-mentioned difficulties, and its purpose is to provide an adjustment mechanism that allows stepless adjustment of the impact amplitude with simple operation.

An embodiment of the present invention shown in the drawings will be explained below. The drawings show an embodiment in which the present invention is applied to a so-called oil bath type rammer, where 1 is a prime mover and 2 is a prime mover.
is a crank mechanism, and 3 is a power transmission mechanism. In this embodiment, the power transmission mechanism 3 includes a pulley 4 provided on a centrifugal clutch on the prime mover side, a pulley 5 provided on a crankshaft 16 on the crank mechanism side, and both pulleys. It is configured as a belt transmission mechanism consisting of a belt 6 wrapped around belts 4 and 5.

Also, 7 is a ramming shoe for compacting the ground, 8
9 is a connecting rod that is moved up and down by the crank mechanism 2; 9 is a ram rod whose upper end is connected to the lower end of the connecting rod 8 and is movable up and down while being guided in a guide tube 10 at the bottom of the fuselage; 11 is a ramming shoe 7 at the lower end. is fixed and the upper part is the guide tube 10
It is a sliding tube that is slidably inserted into the sliding tube 11.
The ram rod 9 is inserted inside.

Further, an enlarged diameter portion 91 is provided at the lower end of the ram rod 9 inserted into the sliding tube 11 in this manner, and springs 12 are provided at the upper and lower portions of the sliding tube 11 bordering on this expanded diameter portion 91. The ramming shoe 7 is made to vibrate up and down by transmitting the vertical movement of the ram rod 9 to the sliding tube 11 via the spring 12.13.

Further, the guide cylinder 10 and the sliding cylinder 11 are covered from the outside with an elastic cover unit 14, and lubricating oil 15 is sealed inside the cover unit 14.

In the above configuration, in the present invention, the crankshaft 16 constituting the crank mechanism 2 is made up of a cylinder body 17 having an eccentric hollow part 171 and a shaft body 18 rotatably fitted into the hollow part 171 of the cylinder body 17. It is composed of

That is, the hollow part 171 of the cylinder 17 is provided eccentrically by S from the cylinder core A of the cylinder 17, and the shaft 18 is fitted into this hollow part 171 and rotates in the radial direction within the hollow part 171. Rotation is possible.

The crankshaft 16 having such a structure is rotatably provided by attaching its cylindrical body 17 via a bearing 21 to a bearing portion 20 provided in a crankcase 19 in the upper part of the machine body.

A cylindrical body 17 constituting the crankshaft 16 is provided with a pulley 5, which is an element of a power transmission mechanism 3 for transmitting power from the prime mover 1, and a crank arm 22 constituting the crank mechanism 2 is provided on the shaft body 18. and a crank pin 23 are coupled.

A connecting and fixing device 24 for integrally connecting and fixing the cylindrical body 17 and the shaft body 18 is provided at one end of the crankshaft 16, that is, at the end opposite to the end on the side where the crank arm 22 is formed.

This connecting and fixing device 24 is configured to removably connect the cylinder body 17 and the shaft body 18 by bringing friction plates 25 and 26 provided on the cylinder body 17 and the shaft body 18 into close pressure contact. In the embodiment, it is configured as a multi-disc clutch structure.

In order to provide such a connecting and fixing device 24, the shaft body 18 is provided with a protruding shaft portion 181 that protrudes outward from one end of the cylindrical body 17, and the distal end portion of the protruding shaft portion 181 is provided with a bolt. The portion 182 and the portion on the main body side of the shaft body 18 are configured as a square portion 183.

Furthermore, a threaded portion 172 is provided on the outer periphery of the one end of the cylindrical body 17, and a short cylindrical case body 27 having a female threaded portion 271 inside one end is attached to the threaded portion 172 via the female threaded portion 271. In this state, the case body 27 protrudes outward from the end of the cylindrical body 17 so as to surround the square portion 183 of the protruding shaft portion 181.

Therefore, friction plates 26 are provided inside the square part 183 of the protruding shaft part 181 and the case body 27 surrounding the square part 183, respectively.
a , 26 b , 26 C and 25 a , 25 b
, 25 C are installed adjacent to each other alternately,
This forms a multi-disc clutch structure.

That is, the friction plates 25a, 25b, and 25c provided on the cylindrical body 17 side, that is, on the case body 27, have a ring shape,
It is provided inside the case body 27 so as to protrude in the case body centripetal direction, and the shaft body 18 side, that is, the square part 1
The friction plate 26 provided at 83 has a circular shape and is fitted into the square portion 183 through its center.

Note that the friction plates 25 a , 25 b , 25 C and 26 a.

The widths of 26b and 26C are within a certain range so as not to impede relative rotation between the cylinder 17 and the shaft 18 and to prevent the friction plates from coming off each other.

Therefore, the friction plates 25a, 25b, 25
As a mechanism for bringing C, 26a, 26b, and 26C into close pressure contact, a presser plate 2 is provided on the square portion 183.
8 is fitted and inserted so as to be able to slide in the axial direction, and the bolt part 1
A handle-shaped fastener 29 that presses the presser plate 28 is screwed onto 82, and by tightening the fastener 29, the friction plates 25 a and 25 b are moved through the presser plate 28 .
, 25 C and 26 a , 26 b , and 26 C are brought into close contact with each other, thereby making the cylindrical body 1 mutually rotatable.
7 and the shaft body 18 are connected and fixed, and the crankshaft 16 is integrated.

The end of the crankshaft 16 provided with the above-mentioned connection and fixing device 24 protrudes from the side of the crankcase 19, and a cover 3 is provided on that part of the crankcase 19.
0 is removably attached so as to wrap around the protruding portion.

In other drawings, 31 is a seal.

According to the adjustment mechanism configured as described above, since the shaft body 18 having the crank arm 22 and the crank pin 23 is fitted into the eccentric hollow portion 171 of the cylinder body 17, the cylinder body of the shaft body 18 By selecting a position in the circumferential direction relative to the crank pin 17 and fixing the shaft body 18 and the cylinder body 17, a desired turning radius of the crank pin can be obtained.

That is, to explain this based on FIG. 5, when the cylinder body 17 and the shaft body 18 are connected and fixed in the state shown in FIG.
The turning radius of No. 3 becomes the maximum Pl, and as a result, the impact amplitude of the ramming shoe 7 becomes the maximum.

Conversely, the position of the shaft body 18 with respect to the cylinder body 17 in the circumferential direction is
If the shaft body 18 and the cylinder body 17 are connected and fixed in the state shown in FIG. 5 by changing the state of FIG.
The turning radius of the crank pin 23 becomes the minimum P2, and as a result, the impact amplitude of the ramming shoe 7 also becomes the minimum.

Therefore, by appropriately selecting the circumferential position of the shaft body 18 with respect to the cylinder body 17 within the range of 180° between a and l in FIG. Therefore, any desired impact amplitude of the ramming shoe 7 can be obtained steplessly through the strokes of the connecting rod 8 and the ram rod 9.

In addition, in this embodiment, the ramming shoe 7 is connected to the spring 12.
．． Therefore, the vertical movement stroke of the connecting rod 8 and ram rod 9 and the striking amplitude of the ramming shoe 7 do not necessarily match, but the striking amplitude of the ramming shoe 7 is the same as that of the connecting rod 8 and the ram rod 9. Therefore, if the relationship between the stroke and the impact amplitude as described above is clarified in advance, the desired impact amplitude can be obtained by adjusting the stroke appropriately.

The adjustable range of the impact amplitude as described above is determined by the eccentricity S of the hollow portion 171 of the cylinder 17, and the larger the eccentricity S, the wider the adjustable range.

Therefore, it is necessary to determine the eccentricity S while considering the range of strength of the required impact force.

The positional adjustment of the shaft body 18 and the cylinder body 17 in the circumferential direction as described above is performed by the following operation.

That is, from the state where the shaft body 18 and the cylinder body 17 are integrally connected and fixed, the friction plate 25a is first loosened by loosening the fastener 29 that constitutes the connection and fixing device 24.

25 b , 25 C and 26 a , 26 b , 26
c, and the shaft body 18 and the cylinder body 1 are released.
7 and are in a state where they can rotate with respect to each other.

Here, crank pin 23 is running? - When the machine is at rest, it is always located at the top dead center due to the balance between the elastic force of the springs 12 and 13 and the weight of the machine. Therefore, in order to adjust the positions of the cylinder body 17 and the shaft body 18, Cylinder 1
A pulley 5 integrally provided on the shaft 17 is rotated by hand, thereby appropriately rotating the cylindrical body 17 with respect to the shaft body 18.

When the rotation is completed to a predetermined angle, the fasteners 29 are used to tighten the friction plates 25 a , 25 b , 25 .
C, 26a, 26b, and 26C are brought into close pressure contact, and the shaft body 18 and the cylinder body 17 are integrally connected and fixed by the frictional force.

In order to facilitate such a position adjustment operation, as shown in FIG. The holding plate 28 is provided with an arrow pointing to the scale,
It is preferable that the rotation angle of the cylindrical body 17 with respect to the shaft body 18 can be selected using the scale and the arrow.

In the configuration of this embodiment described above, the connecting and fixing device 24 is not limited to a multi-plate clutch structure, but may be of any other suitable configuration, such as a single-plate clutch structure with a high friction coefficient. However, in some cases, a flat washer or the like may be interposed between the friction plates.

Further, it goes without saying that the mechanism for tightening the friction plate is not limited to the nut type as in this embodiment, but may be any other suitable type.

Further, in this embodiment, the present invention is applied to a so-called oil bath type rammer, but it goes without saying that it can be applied to other types of rammers, and the power transmission mechanism 3 is a gear mechanism. , a chain mechanism, etc.

According to the above-described impact amplitude adjustment mechanism of the present invention, the variable range of the impact amplitude is determined by the amount of eccentricity of the hollow part of the cylinder, so by appropriately selecting the amount of eccentricity, it is possible to widen the variable range. Furthermore, by simply adjusting the circumferential position of the cylindrical body and shaft body that make up the crankshaft, it is possible to obtain any desired impact amplitude steplessly. It is possible to compact the ground by applying a striking force, and since the adjustment operation is extremely easy, it has an excellent practical effect of improving workability at the site.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is an explanatory diagram showing a longitudinal section of a rammer to which the mechanism of the invention is applied, Fig. 2 is an explanatory diagram showing a cross section thereof, and Fig. 3 is an explanatory diagram showing a longitudinal section of a rammer to which the mechanism of the invention is applied. The figure is a longitudinal cross-sectional view showing the mechanism of the present invention, Figure 4 is an explanatory diagram showing the connection and fixing device with the fastener removed, and Figures 5a and b are the connection state of the shaft body and cylinder body and the crank pin. FIG. In the figure, 1 is a prime mover, 2 is a crank mechanism, 3 is a power transmission mechanism, 7 is a ramming shoe, 16 is a crankshaft, 1
7 is a cylinder body, 18 is a shaft body, 22 is a crank arm, 23 is a crank pin, 24 is a connecting fixing device, 25 a , 25 b
, 25C, 26a, 26b, and 26C are friction plates, 29 is a fastener, and 171 is a hollow portion.

Claims (1)

[Scope of utility model registration request] In a rammer having a structure in which the driving force of a prime mover is transmitted to a crank mechanism via a power transmission mechanism, and a lower ramming shoe is vibrated vertically by the vertical movement obtained by the crank mechanism, a hollow portion eccentrically disposed about the crankshaft of the crank mechanism is provided. and a shaft body rotatably fitted into a hollow portion of the cylinder body, the cylinder body is provided with a transmission element constituting the power transmission mechanism, and the shaft body is provided with a crank mechanism. The crankshaft is provided with a crank arm and a crank pin constituting the cylinder body, and the crankshaft also includes friction plates provided on the cylinder body and the shaft body, respectively, and a fastener for bringing the friction plates into close pressure contact. A striking amplitude adjustment mechanism for a rammer, characterized in that it is provided with a connecting and fixing device that detachably connects and fixes a body and a shaft body.