JPH0219649Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic tensioning device for a wrapped transmission member, which automatically tensions a wrapped transmission member such as a transmission chain, belt, or rope.

(Prior Art) A winding transmission member tensioning device that has been commonly used in the past is designed to apply tension to the winding transmission member by pressing the tensioning member using a spring, screw, weight, etc. However, it was necessary to adjust the tensioning device each time the wrapped transmission member stretched, which was a problem.

(Problems to be solved by the invention) The present invention has been made in view of the above-mentioned circumstances, and it wraps around the tension member and automatically follows the elongation of the transmission member, so that the tension member is kept at a constant level without power. The object of the present invention is to provide an automatic tensioning device for a wrapped transmission member that can apply pressure and automatically avoid overload.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the wrapped transmission member automatic tensioning device according to the present invention tensions the transmission member wound around the driving member and the driven member. The member is attached to the output piston of the first hydraulic cylinder, and a weight is applied to the input piston of the second hydraulic cylinder which is communicated with the first hydraulic cylinder, whereby the pressure in both hydraulic cylinders is reduced by the weight. This device is characterized in that the tension member is pressed through a medium liquid.

(Function) The wrapped transmission member automatic tensioning device according to the present invention is configured as described above, so that the tensioning device is connected to the inside of the second hydraulic cylinder and connected thereto by the weight acting on the input piston. Hydraulic pressure is generated in the pressure mediating liquid within the first hydraulic cylinder, and this hydraulic pressure presses the output piston and the tensioning member attached thereto, thereby tensioning the winding transmission member.

Further, when the wrapped transmission member is extended, the tension member is automatically made to follow the wrapped transmission member by the hydraulic pressure of the weight, and a constant pressure is applied to the tension member by the weight.

Furthermore, when an overload is applied to the wrapped transmission member, the tension member retreats against the hydraulic pressure caused by the weight, and the shock associated with the overload is absorbed by the oil in the cylinder, so the overload is automatically and silently removed. This will be avoided.

(Example) Hereinafter, an example of the automatic transmission chain tensioning device according to the present invention will be described in detail with reference to the drawings.

In the figure, reference numeral 20 denotes a driving chain consisting of a roller chain or the like as a winding transmission member, and the driving chain 20 serves as a driving member fixed to an output shaft 21 of a prime mover (not shown) placed on the frame 10. It is wound around a drive sprocket 22 and a driven sprocket 24 as a driven member fixed to an input shaft 23 of a device (not shown). 30 is a tension sprocket as a tension member that tensions the drive chain 20;
As shown in FIG. It is movably supported in guide holes 13, 13 provided in the horizontal direction. The shaped movable body 32 has a stepped portion 14 protruding from the lower part of the inner side of the side plates 11, 11 of the frame 10.
The rear plate 34 of the moving body 32 is movably supported on the rear plate 12 of the frame 10.
It is attached to the output piston 41 of the first hydraulic cylinder 40 as the first hydraulic cylinder equipped in the
The first hydraulic cylinder 40 is connected to a second hydraulic cylinder 50 as a second hydraulic cylinder through a conduit 42, and the output piston 41 of the first hydraulic cylinder 40 and the input piston 51 of the second hydraulic cylinder 50
Oil as a pressure medium fluid is trapped between the input piston 51 and the input piston 51, and a weight 60 is applied to the input piston 51. In order to cause the weight 60 to act on the input piston 51, the input piston 51 is pushed down with the weight 60 as shown in FIG. 1, or the input piston 51 is pulled down with the weight 60 as shown in FIG. There are cases.
Note that 70 is an oil filler plug provided at an oil filler port for supplying oil to the first hydraulic cylinder 40 and the second hydraulic cylinder 50, and 80 is a valve provided in the conduit 42.

The automatic transmission chain tensioning device devised by the present invention is
Since it is configured as described above, when the weight 60 is not applied to the input piston 51, no pressing force is applied to the tension sprocket 30, but
In this state, the valve 80 is closed and the input piston 51
When the weight 60 is applied to the second hydraulic cylinder 50, the weight 60 generates hydraulic pressure in the oil in the second hydraulic cylinder 50. Next, after starting the prime mover (not shown), valve 8 is turned on.
When 0 is opened, hydraulic pressure is generated by the weight 60 in the oil in the first hydraulic cylinder 40 via the pipe 42,
This oil pressure presses the tension sprocket 30 via the output piston 41 and the movable body 32 attached thereto, and the drive chain 20 is tensioned.
The state shown in Fig. 1 is reached, and the driven sprocket 24
is rotated.

Further, when the drive chain 20 is extended during driving, the input piston 51, the second hydraulic cylinder 50, and the first hydraulic cylinder 40 are moved by the weight 60.
The oil inside and the output piston 41 work together to automatically cause the tension sprocket 30 to follow the drive chain 20, and a constant pressure is applied to the tension sprocket 30 by the weight 60.

Furthermore, when an overload is applied to the drive chain 20 during driving, the tension sprocket 30 is retracted against the pressing force of the weight 60, as shown in FIG. As well as being absorbed by oil, the output piston 4
1, the oil in the first hydraulic cylinder 40 and the second hydraulic cylinder 50, and the input piston 51 move together, so that overload is silently and automatically avoided. 60 exerts a constant pressure.

(Effects of the invention) As is clear from the above explanation, according to the invention, the tension member can be wrapped around the transmission member to automatically follow the elongation of the transmission member, and a constant pressure can be applied to the tension member without power. It has now become possible to provide an automatic tensioning device for a wrapped transmission member that can automatically and silently avoid overload.

[Brief explanation of the drawing]

The drawings show an embodiment of the automatic transmission chain tensioning device according to the present invention, in which Fig. 1 is a partially cutaway side view, and Fig. 2 shows another modification of the action of the weight. Figure 3 is a partially cutaway side view showing a state in which overload has been avoided; Figure 4 is a side view of the main parts shown;
The figure is an enlarged sectional view taken along line AB in FIG. 3. 20: Drive chain, 22: Drive sprocket, 24: Driven sprocket, 30: Tension sprocket, 40: First hydraulic cylinder, 41: Output piston, 50: Second hydraulic cylinder, 51: Input piston, 60: Weight.

Claims (1)

[Scope of utility model registration request] A tensioning member for tensioning the transmission member wound around the driving member and the driven member is attached to the output piston of the first hydraulic cylinder, and a weight is attached to the input piston of the second hydraulic cylinder communicated with the first hydraulic cylinder. 2. An automatic tensioning device for a wrapped transmission member, characterized in that the tensioning member is pressed by the weight through pressure mediating liquid in both hydraulic cylinders.