JPS5827422B2 - Detection device for wrapped transmission members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection device used to detect damage or speed of a winding transmission member such as a belt.

In machine tools and bearing testing machines, when power is transmitted by a wrapped transmission member such as a belt, in order to obtain signals for speed control, starting, and stopping of the power device,
A belt detection device may be used to detect the speed or breakage of the belt.

However, although various types of such detection devices have been developed in the past, they have problems such as being complicated in structure or being expensive.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a winding transmission member detection device that is simple in structure, reliable in operation, and inexpensive.

Corresponding to this purpose, the detection device for a wrap-around transmission member of the present invention includes a fixed shaft having a hollow part bored almost vertically, a displacement member inserted into the hollow part of the fixed shaft, and a fixed shaft. A position for restraining a rotating body that is supported by a shaft via a bearing and rotates by being driven by a wrap-around transmission member that is the test object, and a displacement member that is swingably supported on the rotating body via a pivot shaft. and a weight that can be oscillated between the position and the unrestricted position, and whose center of gravity is outside the rotation axis of the rotating body and above the pivot axis.

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment.

In FIGS. 1, 2, and 3, 2 is a belt detection device, and the belt detection device 2 is disposed on the upper plate 4 of the frame 3 at a fixed position along the belt 1.

The belt detection device 2 has a fixed shaft 5.

The fixed shaft 5 consists of an upper part 6 and a lower part 7 which are coaxially screwed together.

The lower part 7 is substantially cylindrical and has a flange 8 at its lower end, by which it is fixed to the upper plate 4 of the frame 3 by bolts.

An internal thread 9 is formed inside the lower part 7.

The upper part 6 is a substantially cylindrical body having a hollow part 11 penetrating in the axial direction, and is provided with a male thread 12 around the lower end and is screwed into the lower part 7. The inner ring of the bearing 13 is held in cooperation between the two.

The fixed shaft 5 is located vertically, and a long pin 1 is provided in the hollow part 11.
4 is loosely inserted.

The pin 14 vertically passes through the hollow part 11 of the fixed shaft 5 and can be displaced relative to the fixed shaft. 15 comes into contact with the top of the fixed shaft 5, so that it does not fall from the hollow part 11.

The lower end of the pin 14 protrudes from the hole 16 in the upper plate 4 of the fixed foot 5 and the frame 3 and comes into contact with the lever 18 of the microswitch 17.

The microswitch 17 is attached to the frame 3.

A pulley 19 is attached to the outside of the fixed shaft 5 via a bearing 13.

The pulley 19 is fixed to the outer ring of the bearing 13 and is in contact with the belt 1 on its outer peripheral surface, and is driven and rotated by the belt 1 when the belt 1 is running.

A bracket 21 is attached to the upper end surface of the pulley 19, and a weight 23 is swingably supported on the bracket 21 via a pivot shaft 22.

The weight 23 is in a position shown by a solid line in which it contacts the head 15 of the pin 14 and presses the pin 14 downward, and in a position where it does not contact the head 15 and presses the pin 14 downward.
Therefore, the pin 14 can be displaced between the position shown by the chain line 23' where the pin 14 is not restrained.

Further, the weight 23 has a center of gravity between the rotation center of the pulley 19 and the pivot shaft 22, and
It has been adjusted to be higher up.

In the belt detection device 2 configured as described above, under normal conditions, the belt 1 contacts the pulley 19, and as the pulley 19 rotates, the weight 23 also rotates.

In this case, as shown in FIG. 4, m: mass of the weight 23 r: horizontal distance between the center of gravity of the weight 23 and the rotation center of the pulley 19 R: horizontal distance between the double weight 23, the center of gravity, and the pivot shaft 22 ω: Rotational angular velocity of pulley 19 h: Vertical distance from pivot shaft 22 to center of gravity g: Gravity (if mouth speed changes), torque Tc −m for one weight 23 due to centrifugal force
rωh and the torque Tg''mgR due to gravity act in opposite directions, but if m, r, and h are determined so that Tg<Tc at a predetermined rotational speed ω,
At a predetermined speed of the belt 1 at the above-mentioned ω, the weight 23 assumes the elevated position shown by the chain line 23' in FIG.
The weight 23 is separated from the head 15 and does not restrain the pin 14,
The pin 14 is also pushed up by the lever 18 of the microswitch 17, which has an elastic restoring force, and assumes the raised position 14'.
The microswitch 17 connects the electric circuit and the belt 1 continues to run.

Now, suppose belt 1 is damaged due to an accident and pulley 19
, the pulley 19 stops without being driven, the rotational torque Tc due to the centrifugal force acting on the weight 23 disappears, and the weight 23 moves to the position shown by the solid line in FIG. 2 due to gravity. It falls, contacts the head 15, pushes down the pin 14, and the pin 14 pushes down the lever 18 against the restoring force, thereby turning the microswitch off, cutting off the electric circuit, and removing the belt 1. The prime mover that was driving the engine stops.

In this way, the belt detection device of the present invention can quickly operate a microswitch or the like depending on the damage or speed of the belt.

Moreover, because of its simple structure, it operates reliably without failure.
And the price will also be low.

[Brief explanation of drawings]

Figure 1 is a plan view of the belt detector, Figure 2 is a front view of the belt detector, Figure 3 is a side view of the belt detector, and Figure 4 shows the force acting on the weight of the belt detector. It is a line diagram. 1...Belt, 2...Belt detector,
5...Fixed shaft, 11...Hollow part, 13
...Bearing, 14...Pin, 17...
... Micro switch, 22 ... Pivot shaft, 2
3... Weight.

Claims (1)

[Claims] 1. A fixed shaft having a hollow part bored almost vertically, a displacement member inserted into the hollow part of the fixed shaft, and a winding transmission member supported by the fixed shaft via a bearing and serving as a test object. The rotating body rotates when driven by the rotating body, and the displacement member, which is swingably supported by the rotating body via a pivot shaft, can be oscillated between a restraining position and a non- restraining position. A detection device for a wrap-around transmission member, comprising: a weight having a center of gravity outside the rotation axis of the rotating body and above the pivot shaft.