JPH0138508Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tension meter for power transmission belts.

Generally, when a transmission belt is wound between pulleys, it is necessary to apply a cut-off tension of a certain level or more in order to generate the necessary transmission friction force between the belt and the pulleys.

Conventionally, as a measuring device to determine whether or not the initial tension of the belt is appropriate, two fixed fulcrums are placed at regular intervals along the transmission belt mounted on a pulley, and a device is placed at the center of this point that acts perpendicularly to the belt. A system with a movable fulcrum that converts the rigidity of the belt over a certain span into initial tension based on the load applied to the movable fulcrum and the amount of belt deflection, or a transmission belt wound between pulleys. , a mechanism is known in which a load is applied from the perpendicular direction to the transmission belt, and the load is converted into initial tension based on the load when the transmission belt reaches a certain amount of deflection, but the former method is It consists of a fixed fulcrum, a movable fulcrum, and a load measuring device, and although it is suitable for precision measurements, it is a large device and cannot be used in narrow places, for example, to measure the tension of belts such as automobile fan belts. Also, it has the disadvantage that it is expensive and therefore not common, but the latter type is called a so-called pencil type and is very easy to use, so it has the advantage that it can be used even in narrow spaces. However, it has the disadvantage that it is very difficult to measure and read the deflection load and deflection amount of the transmission belt at the same time, the error is very large, and only rough measurements can be made.

In view of the above-mentioned drawbacks, this invention has been developed to make the initial tension of a power transmission belt very easy to measure, and to keep the error of the measured value within a practical range. The purpose of this device is to provide a compression meter, in which an inner cylinder with a load scale required for compression of the elastic spring engraved on the outer periphery is fitted and inserted into an outer cylinder via an elastic spring. A ring body is fitted onto the outer circumferential surface of the inner cylinder and is in contact with the end surface of the outer cylinder and can slide along the outer circumferential surface of the inner cylinder in the axial direction. The inner cylinder end surface is used as a cantilever support point in a direction perpendicular to the inner cylinder, and arms that rotate within a rotation range including the inner cylinder central axis about the fulcrum are extended in opposite directions. This is a characteristic feature.

This invention will be explained below using examples.

FIG. 1 is a partial sectional view of an embodiment of this invention.

The tension meter A for power transmission belts (hereinafter simply referred to as "tension meter") of this invention has a load scale 3 required for compression of the elastic spring 2 in a cylindrical outer tube 1 via an elastic spring 2. An inner cylinder 4 engraved on the outer periphery 4A is fitted and inserted, and is in contact with the end face 1A of the outer cylinder 1 on the outer periphery 4A of the inner cylinder, and extends in the axial direction (arrow M) on the outer periphery 4A of the inner cylinder. A ring body 5 that can slide along the inner cylinder 4 is fitted onto the end face 4B of the inner cylinder 4.
An arm that rotates in a direction (arrow N) perpendicular to the axis 4C of the inner cylinder, using the inner cylinder end face 4B as a cantilever support point, and rotating around this fulcrum 6 within a rotation range 7 that includes the inner cylinder central axis 4C. 8, 8 extend in opposite directions and are attached.

In the above embodiment, the lower edges 8 of the arms 8, 8
A and 8A are surfaces perpendicular to the axis 4C.

Further, reference numeral 9 in the figure is a ring body which is fitted, for example, with a screw, to the end surface of the outer cylinder 1, and is attached to prevent the inner cylinder from slipping out.

Next, the operation of the embodiment of this invention will be explained.

First, as shown in Fig. 2, after setting the arms 8, 8 so as to be perpendicular to the axis 4C, the outer cylinder 1 of the tension meter A is supported, and the transmission wire wound between the pulleys B, B is set. The inner cylinder 4 is arranged so that its axis 4C is perpendicular to the belt V, and then the outer cylinder 1 is strongly pushed in the axial direction as shown in FIG.

At this time, the outer cylinder 1 slides along the inner cylinder 4 against the elastic force of the elastic spring 2, and at the same time, the ring body 5 is pushed by the end surface 1A of the outer cylinder 1, causing the inner cylinder to move. 4 Slide on the top.

Further, the transmission belt V is bent and deformed at the apex of the inner cylinder 4 due to the load when the outer cylinder 1 is pushed in, and the arms 8, 8 are simultaneously rotated along with this bending deformation.

After that, when the tension meter A is gently separated from the transmission belt V, the load applied by the position of the ring body 5 that has moved along the inner cylinder 4 will be transferred to the transmission belt at that time, as shown in Fig. 4. The amount of deflection of V is recorded by the arms 8, 8.

At this time, the initial tension of the transmission belt V is To,
If the pressing load is F and the bending angle of arm 8 is θ, then the relationship between these can be expressed as To=F/2・cosθ/2... and cosθ/2=δ/l... (where l: fulcrum The distance between 6 and arm 8,
δ: horizontal movement distance of the tips of arms 8, 8), the initial tension To is calculated from the formula as To=F/2・δ/l=F・l/2・δ..., and the arm 8, The initial tension To can be easily calculated by finding δ by applying a ruler or the like between the tips 8A and 8A of the 8.

Further, in order to facilitate the determination of the value of δ, a length scale may be provided on the outer periphery of the inner cylinder along the axial direction, separately from the load scale 3, or in combination.

This idea is structured as above, so
When measuring the initial tension of a power transmission belt, no large-scale equipment is required at all, so it can be used in narrow spaces, and it is possible to simultaneously read the belt deflection load and deflection amount necessary for initial tension measurement. Anyone can easily perform the measurement without relying on skill or intuition, and most of the errors included in the measurement results are only measurement errors when measuring the distance between the ends of the arms. Since it can be made sufficiently small if care is taken, it has the practical effect of allowing accurate values to be obtained.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view of an embodiment of this invention, Figure 2 is a partial sectional view of an embodiment of this invention.
4 to 4 are conceptual diagrams illustrating the usage state of the embodiment of this invention. A... Tension meter for power transmission belt, 1...
Outer cylinder, 1A... Outer cylinder end surface, 2... Telescopic spring, 3...
...Load scale, 4...Inner cylinder, 4A...Inner cylinder outer circumference, 4
B... Inner cylinder end surface, 5... Ring body, 6... Fulcrum,
7...Rotation range, 8...Arm, B...Pulley, V
...Transmission belt.

Claims (1)

[Scope of utility model registration request] An inner cylinder whose outer periphery is engraved with a load scale required for compression of the elastic spring is inserted into the outer cylinder via a telescopic spring, and the outer peripheral surface of the inner cylinder is in contact with the end surface of the outer cylinder,
A ring body that can slide on the outer circumferential surface of the inner cylinder in the axial direction is fitted onto the inner cylinder end face, and the inner cylinder end face is attached to the inner cylinder end face in a direction perpendicular to the axis of the inner cylinder. 1. A tension meter for a power transmission belt, characterized in that the arms have a cantilever support point, and each arm extends in opposite directions and rotates around the support point within a rotation range that includes the inner cylinder center axis.