JPS5855382B2 - Propulsion imparting mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propulsive force imparting mechanism using spring torque.

This type of mechanism is used, for example, in a chain tensioner, where the object is intended to move with a certain force in one direction, but requires properties similar to those of a rigid body in the opposite direction.

In other words, when the chain becomes loose due to stretching or wear during use, the chain tensioner applies a certain tension to the chain by pressing it in one direction. For the opposite direction (reaction force direction), a custom-made product that is close to a rigid body is desirable.

Conventionally, for example, in the case of chain tensioners, there are types that are readjusted manually according to the stretch of the chain, and types that automatically adjust the stretch, but the former is relatively inexpensive but requires troublesome maintenance. Moreover, the latter has disadvantages such as the tendency to generate abnormal noise, and the latter has the disadvantage that the entire mechanism is complicated and expensive because it uses hydraulic pressure.

The present invention was made in view of the above circumstances, and is capable of properly securing propulsion force with a simple mechanism, has a custom design that is close to a rigid body against reaction force, and does not require maintenance. The present invention aims to provide a new propulsion force imparting mechanism that utilizes spring torque.

The present invention will be described in detail below based on embodiments shown in the drawings.

This embodiment is an example in which the propulsive force imparting mechanism according to the present invention is employed in a belt tensioner.

1.2 is a pulley between which the belt 3 is stretched.

A belt pressure plate 4 is fixed to one end of a shaft 6 which is slidably mounted on a bearing 5.

7 is a propulsion force imparting mechanism according to the present invention, and this mechanism 7 is connected to a substrate 8.
and a case having an open edge fixed to the substrate 8, a core bar 10 rotatably mounted through holes drilled in each of the base plate 8, and a case 9 having an open edge fixed to the base plate 8; A lever 11 that is in contact with the other end of the shaft 6 is loosely inserted into the core metal 10, and one end is fixed to a split groove (not shown) formed in the core metal 10, and the other end 13a is provided inside the case 9. A torsion spring 13 attached to the drilled hole of the protrusion 12 and the torsion spring 1
One end 14 is located below the core bar 10 and is inserted into the core bar 10.
A is attached to the drilled hole of the protrusion 15 provided inside the case 9, and the other end 14b is simply inserted into the elongated hole 16 provided in the case 9 to form a free end with a tightening margin for the core bar 10. It consists of a molded clutch spring 14.

This "clutch spring 14 formed with a tightening margin with respect to the core metal 10" is a coil spring having an inner diameter smaller than the outer diameter of the core metal 10 in a free state, and the coil spring is rotated in the unwinding direction. The coil spring is inserted into the core bar 10 while expanding its inner diameter by rotating it, and then the rotation is released and the coil spring tries to return to its free state by decreasing its inner diameter, but the inner circumference of the coil is This refers to a coil spring that is brought into contact with the metal core 10 and inserted onto the metal core 10 without reducing the inner diameter of the coil below the outer diameter of the metal core 10.

Therefore, the clutch spring 14 is attached to the core metal 10 with a certain amount of tightening force.

Note that 17 is a set pin, which is detachably attached to the upper part of the case 9.

In the above configuration, the propulsion force imparting mechanism 7 uses the torsion spring 13
When set on the core bar 10 and the case 9, the lever 11 is forcibly rotated in the tightening direction of the torsion spring 13 (in the direction of arrow A), and the set pin 17 is rotated while generating an appropriate spring torque on the spring 13. Set the lever 11 to prevent it from rotating in the opposite direction to the forced rotation, and then attach the clutch spring 14 and attach it to the end of the core bar 10 and the base 8 of the case 9. conduct.

As described above, since the clutch spring 14 is externally fitted onto the core metal 10 with a tightening force, a frictional force is generated between the clutch spring 14 and the clutch spring 14 when the core metal 10 rotates.

The above-mentioned frictional force becomes larger or smaller depending on the rotation direction of the core metal 10.

That is, when the core metal 10 rotates in the unwinding direction of the clutch spring 14, the coil diameter of the spring 14 is expanded, which reduces the above-mentioned frictional force, and conversely causes the clutch spring 14 to expand. Spring 1 when rotated in the tightening direction
Since the diameter of the coil No. 4 is reduced, the above-mentioned frictional force increases.

Therefore, the core metal 10 freely rotates while slipping in the direction of unwinding the clutch spring 14, but on the contrary, its rotation is locked in the direction of tightening the clutch spring 14.

When the clutch spring 14 removes the set pin 17 and the spring torque of the torsion spring 13 acts on the core metal 10 to rotate and energize the core metal 10, the clutch spring 14 rotates the lever 11 in the direction of arrow B. When the core metal 10 is rotated in the direction of the reaction force so that the metal 10 rotates freely and a reaction force acts on the lever 11 in the direction opposite to the rotation (in the direction of arrow A), the core metal 10 is rotated in the direction of the reaction force. It is attached to lock the rotation of 10.

In the above embodiment using the propulsive force imparting mechanism according to the present invention, when the set pin 17 is removed, the torsion spring 13
The spring torque acts on the core metal 10 to urge the lever 11 in the direction of arrow B with an appropriate propulsive force, thereby constantly pressing the belt 3 in one direction via the shaft 6 and the pressure plate 4.

Therefore, the belt 3 always maintains an appropriate tension, and the pulleys 1,
It is strung between the two.

When a reaction force in the direction of arrow C acts on the pressure plate 4, the core metal 10 attempts to rotate in the direction of the reaction force via the lever 11, but this rotation is prevented by the clutch spring 14.

That is, the propulsive force imparting mechanism 7 according to the present invention has characteristics similar to a rigid body with respect to the reaction force described above.

As described above, according to the propulsive force imparting mechanism according to the present invention, despite the extremely simple structure that utilizes spring torque, it is possible to properly secure the propulsive force, and moreover, the On the other hand, it has characteristics close to that of a rigid body, and since the spring torque is always acting on it, it is possible to always impart a certain propulsion force to the object, so maintenance is not required, and it can be applied to belt tension etc. In this case, the effect is significant.

[Brief explanation of drawings]

FIG. 1 is a front view of a belt tensioner using a propulsive force imparting mechanism according to the present invention, and FIG. 2 is a side view of essential parts of the same. 1.2...pulley, 3...belt, 4.
...Pressure plate, 5...Bearing, 6...
・Shaft, 7... Propulsive force imparting mechanism, 9...
...Case, 10... Core metal, 11...
・Lever, 13...Torsion spring, 14...
...Clutch spring, 17...Set pin.

Claims (1)

[Claims] 1. A core metal rotatably attached to a substrate, a lever fixed to the core metal, a torsion spring loosely inserted into the core metal, with one end fixed to the core metal and the other end fixed to an appropriate fixing member, a clutch spring which is fitted over the core metal and is molded with a tightness allowance to the core metal with one end fixed to a fixed member as appropriate and the other end free; The clutch spring is rotationally biased by the torque and imparts a propulsive force to the lever, and the clutch spring expands the inner diameter of the spring to rotate the core metal as the core metal rotates due to the spring torque. The spring is free, and is mounted so that when the core metal is rotated in a direction opposite to the rotation direction due to a reaction force against the spring torque, the inner diameter of the spring is reduced to prevent rotation of the core metal. Propulsion imparting mechanism.