JPH0232917Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a belt transmission mechanism for transmitting the rotational output of an engine to a driven pulley via a drive pulley in an engine-powered working machine such as a large tiller.

(Prior Art) In general, an endless belt suspended between the drive pulley and driven pulley of a belt transmission mechanism in an engine-driven working machine such as a large cultivator is always kept under appropriate tension during normal operation, so that power is not interrupted. This is done via the main clutch, but when starting the engine or replacing the endless belt,
These operations are performed after first releasing the tension on the endless belt, and after completing the operations, the endless belt is tensioned again to adjust the tension state of the endless belt.

For example, Utility Model Publication No. 58-24663 is used to quickly and accurately adjust the tension state of this endless belt.
As shown in the figure, the tension arm of the tension pulley of the belt transmission mechanism is made of an adjustment rod with a threaded part carved into it, and an auxiliary adjustment tool with a threaded part of a different pitch than the threaded part of the adjustment rod. It is known that the tension state of the endless belt of the belt transmission mechanism is adjusted by providing a screw adjustment mechanism and rotating the tension arm using the screw adjustment mechanism.

(Problems to be Solved by the Invention) As mentioned above, in the conventional belt transmission mechanism for engine working machines that uses a tension pulley to maintain and adjust the tension of the belt, the long-term Due to use or due to mud, dirt, etc. adhering to the rotation support, the tension pulley may no longer rotate smoothly and a so-called locked state may occur, in which belt slip increases.

This locked state often does not cause much trouble in driving the general load itself, so it is difficult to detect it early, and there is a problem in that if this state continues, belt wear increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a belt transmission mechanism that can quickly detect slippage of the belt relative to the tension pulley and prevent belt wear.

(Means and effects for solving the problem) In order to solve the above problem, the present invention provides a connection between a driving pulley 4 and a driven pulley 5, to which the output of the engine 2 is transmitted via a clutch mechanism 6 for power transmission. Discontinuation of the clutch mechanism 6 is detected in a belt transmission mechanism 1 of an engine working machine in which an endless belt 8 is hung between the belts and the endless belt 8 is pressed against both pulleys 4 and 5 by a tension pulley 10. A drive state detection means 11 for detecting whether or not the drive pulley 4 is in a drive state, and a rotation detection means 12 for detecting the rotation speed of the tension pulley 10 are provided, and the output signals of these detection means 11 and 12 are provided. Based on the above, a warning means 1 issues a warning only when the drive pulley 4 is in a driving state and the rotational speed of the tension pulley 10 is below a predetermined value.
8, the slip of the endless belt 8 against the tension pulley 10 is
This can be detected as a speed reduction of 0.

(Embodiments) Preferred embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is an overall configuration diagram showing a belt transmission mechanism of an engine working machine according to the present invention, and FIG. 2 is a diagram showing a rotation sensor.

In the belt transmission mechanism of an engine working machine indicated by 1, 2 is an engine, 3 is its output shaft, 4 is a driving pulley, and 5 is a driven pulley.

A clutch mechanism 6 is disposed between the engine 2 and the output shaft 3, and power transmission from the engine 2 to the output shaft 3 is interrupted.

Engine output is transmitted to the drive pulley 4 through a belt 7 suspended between the drive pulley 4 and the output shaft 3. An endless belt 8 is hung between the driving pulley 4 and the driven pulley 5, and a tension pulley 10, which is urged in the direction of the belt 8 by a spring 9, is pressed against the endless belt 8.

In the belt transmission mechanism 1, the clutch mechanism 6 includes a drive detection switch 11 for the clutch 6, which opens and closes in conjunction with the engagement/disengagement operation of the clutch mechanism.
The switch 11 constitutes drive state detection means for detecting whether or not the drive pulley 4 is in a drive state. Moreover, the tension pulley 1
0 is provided with a rotation sensor 12 for detecting the rotational speed of the tension pulley 10.

As shown in FIG. 2, this rotation sensor 12 is provided on the side of the tension pulley 10, and a plurality of protrusions 13 made of a magnetic material are erected at equal intervals along the circumferential direction of one side of the rotation sensor 12. a rotating body 14,
is fixed to the support part 15 of the tension pulley 10,
It consists of an electromagnetic pickup sensor 17 having a pickup coil 16 attached to its tip.

This electromagnetic pickup sensor 17 is provided so that its pickup coil 16 is located near one side of the rotating body 14, and when the projections 13 pass near the pickup coil 16 as the rotating body 14 rotates, The speed of these protrusions 13... is converted into an electric signal such as a voltage corresponding to the size thereof.

In this way, the rotation sensor 12 is connected to the tension pulley 1.
constitutes a rotation detection means for detecting a rotation speed of 0,
This rotation sensor 12 and the drive detection switch 1
1 output signal is transmitted to warning means 18.

The warning means 18 is activated when the drive pulley 4 is in the drive state according to the output signals of the drive detection switch 11 and the rotation sensor 12, and at this time, the tension pulley 1
It is comprised of a determination circuit 19 that determines whether the rotation speed of 0 is below a predetermined value, and an alarm 20 that issues an alarm based on the output signal of this determination circuit 19.

This discrimination circuit 19 includes, for example, a first switch 19A that opens and closes in conjunction with the opening and closing of a drive detection switch 11 of the clutch 6, as shown in FIG. A second switch 19B that is closed when it is determined that the value is below the value is connected in series,
The alarm device 20 is configured to be connected to the power source 21 when both the first and second switches 19A and 19B are closed. Note that the predetermined value here refers to the rotation of the tension pulley 10 when there is no mud, dirt, etc. attached to the tension pulley 10, and there is almost no slippage between the endless belt 8 and the tension pulley 10. This is a value corresponding to speed.

In the above configuration, according to this embodiment, when the clutch mechanism 6 detects that the rotational speed of the tension pulley 10 is below a predetermined value when the drive pulley 4 is in the driving state, the tension pulley 10 is A slip occurring between the belts 8 can be easily detected.

However, the present invention is not limited to the embodiments; for example, the rotation sensor 12 provided on the tension pulley 10 may be configured with a photo sensor instead of a magnetic sensor. Furthermore, the determination circuit 19 in the warning means 18 may also use, for example, the drive detection switch 11 as the first switch 19A, or the output of the rotation sensor 12 may be determined only when the drive detection switch 11 is in the closed state. It may be configured such that a signal is output.

(Effect of the invention) As is clear from the above explanation, according to the invention,
This is an engine-operated machine that can quickly detect slippage of the belt against the tension pulley that occurs due to long-term use of the tension pulley or due to dirt, dust, etc. adhering to it, thereby preventing belt wear. A belt transmission mechanism can be provided.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing a belt transmission mechanism of an engine working machine according to the present invention, and FIG. 2 is a diagram showing a rotation sensor. In the drawing, 1 is a belt transmission mechanism of an engine working machine, 2 is an engine, 4 is a drive pulley, 5 is a driven pulley, 6 is a clutch mechanism, 8 is an endless belt,
10 is a tension pulley, 11 is a drive state detection means, 12 is a rotation detection means, and 18 is a warning means.

Claims (1)

[Scope of utility model registration request] An engine in which an endless belt is hung between a driving pulley and a driven pulley, to which the output of the engine is transmitted via a clutch mechanism for power transmission, and the endless belt is pressed against both pulleys by a tension pulley. In a belt transmission mechanism of a working machine, a drive state detection means detects whether or not the drive pulley is in a drive state by detecting discontinuation of the clutch mechanism, and a rotation detector detects the rotation speed of the tension pulley. The present invention is characterized by providing a warning means that issues a warning only when the drive pulley is in a driving state and the rotational speed of the tension pulley is below a predetermined value based on the output signals of these detection means. A belt transmission mechanism for an engine working machine.