JPH039339B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a belt transmission mechanism using a V-belt, a flat belt, a toothed belt, etc., by applying a constant tension to the belt suspended on a pulley. This relates to a belt tension device that prevents slippage and tooth skipping.

(Prior Art) As a conventional belt tension device, one in which a rotatable idler pulley is pressed against the back surface or drive surface of the belt by a spring force is widely used.

The tension force applied to the belt of the conventional belt tension device can be adjusted by making the mounting hole of the belt tension device an elongated hole, etc., so that the mounting position can be adjusted by pressing the tension device against the belt. This was done by checking the tension of the belt, determining the mounting position, and fixing the belt tension device to the said mounting position.

(Problem to be Solved by the Invention) Since the conventional belt tension device had the above-described structure, the belt tension was adjusted by temporarily fixing the belt tension device in a predetermined position and then firmly fixing it with bolts, etc. Adjusting the belt tension required considerable skill.

Further, when finely adjusting the belt tension, it is necessary to remove the fixation of the device itself each time, which is quite difficult.

On the other hand, in recent years, due to the demand for improved belt performance and miniaturization of devices, belt transmission mechanisms have often adopted multi-axis drive mechanisms in which a single belt operates multiple axes of equipment. Since it is difficult to control the amount of belt fall of each pulley when the belt is stopped, it has become necessary to adjust the belt tension while the belt is running.

However, it has been dangerous and impossible to adjust the tension using conventional belt tensioning devices while the belt is running.

Therefore, the present invention focuses on such drawbacks of the prior art, and aims to provide a belt tension device that allows easy adjustment of belt tension, fine adjustment of tension, and adjustment of tension while the belt is running. do.

(Means for Solving the Problems) Therefore, the present invention has a small diameter portion having a circular cross section with a small diameter at the base, is thick at the middle portion, and has a small diameter portion at the tip. A core provided with a pin is integrally fixed on the base, and a rotating plate having an idle pulley rotatably fixed at one end is rotatably fixed to the pin of the core, while a small diameter portion of the core A rotation center hole of a rotation base, which has a rotation center hole approximately equal to the diameter of the small diameter portion and is provided with a worm wheel on the side, is rotatably inserted into the groove formed between the bases. , the worm wheel is fitted with a worm gear rotatably supported on the base, and a coil spring is fixed at one end to the rotating base in the middle part of the core body.
The belt tensioner is inserted into a belt tensioning device with the other end locked to a rotating plate.

The belt tension device of the present invention rotates a rotating base to apply a torsional force to a coil spring that is locked to the rotating base, so that the pulley attached to the other end of the coil spring applies the torsional force of the coil spring. It is pressed against the belt and gives tension to the belt.

Further, since the present invention utilizes a worm gear and a worm wheel to apply torsional force to the coil spring, precise adjustment of the torsion angle can be performed simply by rotating the worm gear.

Furthermore, the belt tension device of the present invention has a core body having a thin base portion forming a small diameter portion and a thick middle portion,
The rotating center hole of the rotating base is inserted into the small diameter part of the core, and the rotating base is sandwiched by a groove between the middle part of the core and the base, which prevents the rotating base from floating. always rotates on the same plane.

Therefore, the operation of the rotating base is very stable, and in conjunction with the use of a worm gear, the optimum twist angle can be finely adjusted.

In addition, the worm gear and worm wheel are
Although rotational force is transmitted from the worm gear to the worm wheel, it is difficult to transmit the torque in the reverse direction, so tension can be easily set without the need for special positioning means.

(Example) Specific examples of the present invention will be further described below.

FIG. 1 is a front view of a belt tensioning device in a specific embodiment of the present invention, and FIG. 2 is a view taken in the direction of arrow A in FIG.

In the figure, 1 is a belt tensioning device according to a specific embodiment of the present invention. The belt tension device 1 of this embodiment includes an idle pulley 2, a rotating plate 3, a core 4, a coil spring 5, a rotating base 6, a worm gear 7, and a base 8. The idler pulley 2 has a smooth surface and a bearing 9 at the center, and is rotatably fixed to a shaft 10 provided on a rotary plate 3 via the bearing 9.

The rotary plate 3 to which the shaft 10 is fixed has a disk shape with a boss 11 in the center, and the pin 12 of the core body 7 is inserted into the boss 11, so that it can rotate around the core body 4. can.

That is, the idle pulley 2 is configured to be able to rotate by the bearing 9 and to be able to revolve around the core body 4 . The core body 4 has a cylindrical shape having a pin 12 at its tip into which the rotary plate 3 is rotatably inserted as described above, and the rotary base 6 can be inserted into the lower end fixed on the base 8 as described later. A small diameter portion having a circular outer shape and a small diameter is formed in the pin 12, and an intermediate portion having a larger diameter than both the pin 12 and the small diameter portion is formed between the pin 12 and the small diameter portion.

The groove formed by the base 8 and the small diameter portion of the lower end of the core body 4 has a rotary base 6
is rotatably inserted.

The rotating base 6 has an approximately disk-like outer shape with a hole in the center, and a worm wheel 13 is formed on a part of the side surface. A worm gear 7 rotatably supported on a base 8 with a bearing 14 is locked to the worm wheel 13.

Incidentally, reference numeral 15 provided on the bearing 14 is a set bolt for adjusting the frictional force of the bearing. A coil spring 5 is disposed between the rotary plate 3 and the rotary base 6, with the core body 4 inserted into the hole at the center of the coil spring 5 and fixed without any movement of the center, and both ends of the coil spring 5 being fixed. pin 16,
It is inserted in a state in which it is locked to the rotating plate 3 and rotating base 6 by means of 17. That is, the upper end of the coil spring 5 is locked to the idler pulley 2 via the pin 16, rotating plate 3, and shaft 10. In the belt tensioning device 11 of the present invention, a base 8 is fixed to the periphery of the belt, and with the idle pulley 2 lightly fitted to the back surface or drive surface of the belt, the worm gear 7 is rotated to apply a predetermined tension to the belt. Use it by giving it to someone.

At this time, due to the characteristics of the worm wheel and worm gear, the reduction ratio between the worm wheel and worm gear can be set to a considerably large value, so it is possible to apply strong tension to the belt, and fine adjustment is also easy.

In addition, the worm mechanism can rotate the worm wheel only by rotating the worm gear, and conversely, even if a strong rotational force is applied to the worm wheel, the worm gear acts as a brake and the worm wheel does not rotate or does not rotate. Since it is difficult to set the tension and position it, it is easy.

In the above embodiment, the coil spring 5 is fixed to the rotary plate 3 and the rotary base 6 by the pin 16,
17, but other known means such as abutting the end on a backing plate or providing a hole and inserting the end of the coil spring into the hole may of course be employed. Can be done. The cross-sectional shape of the coil spring wire is generally circular, but if you want to reduce the overall diameter and apply strong tension to the belt, you can achieve your goal by making the cross-sectional shape rectangular. be.

(Effects) The belt tension device of the present invention has a structure in which an idle pulley is locked to one end of a coil spring, and a winding force is applied to the other end to press the idle pulley against the belt. By using a worm wheel and worm gear as the attachment means, it is possible to finely adjust the coil spring winding force, and since the worm gear is unlikely to be unwound by the force of the coil spring, the coil spring winding force can be set easily. It has the effect of being easy. In addition, the belt tension device of the present invention has a small diameter part with a narrow outer diameter at the base of the core part, and the rotating base is sandwiched between the grooves formed between the small diameter part and the base, so that the floating of the rotating base is prevented. The rotating base always operates stably.

Therefore, the belt tension device of the present invention
Combined with the use of a worm gear, this has the effect of allowing fine adjustment of the optimal twisting angle.

[Brief explanation of the drawing]

FIG. 1 is a front view of a belt tension device in a specific embodiment of the present invention, and FIG. 2 is a view taken in the direction of arrow A in FIG. DESCRIPTION OF SYMBOLS 1... Belt tension device, 2... Idle pulley, 3... Rotating plate, 4... Core body, 5... Coil spring, 6... Rotating base, 7... Worm gear, 8... Base, 9... ...worm wheel.

Claims (1)

[Claims] 1 The base has a small diameter part with a small circular cross section, a core body with a thick middle part and a pin at the tip is integrally fixed on the base, and the pin of the core body has a small diameter part at one end. A rotary plate to which the idle pulley is rotatably fixed is rotatably fixed, and a groove formed between the small diameter portion of the core body and the base has a rotation center hole approximately equal to the diameter of the small diameter portion. , a rotation center hole of a rotation base provided with a worm wheel on the side is rotatably clamped and inserted, and the worm wheel is fitted with a worm gear rotatably supported on the base, and 1. A belt tensioning device characterized in that a coil spring is inserted with one end locked to a rotating base and the other end locked to a rotating plate.