JPH0748387Y2 - Belt drive traveling device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device in which a moving part is driven by a belt, and more particularly to a belt safety device.

[0002]

2. Description of the Related Art Conventionally, a straight traveling apparatus has a drive unit provided on a moving body, and a rail and a rack or a ball screw are provided along a girder of a fixed portion, and the moving body which can travel on the rail is described above. There is a drive unit provided with a gear that meshes with a rack or the like, and the movable body is moved along the girder by rotating the gear (for example, the actual flat blade 2-4
780). Further, assuming that the drive section is provided in the fixed section, the movable body is fixed to both ends of the guide shaft that penetrates and slides in the fixed section, the movable body is provided with pulleys, respectively, and the timing belt is fixed to both ends of the fixed section. There is a device in which the timing belt is moved by a drive unit provided in the fixed unit, while being wound around a pulley of a moving body (for example, Japanese Patent Laid-Open No. 61-140665).

[0003]

However, since the device for engaging the rack and the gear has a large weight and a complicated structure, the whole arm becomes large when it is attached to the tip of the arm of the industrial robot. was there. Also,
Although the device driven by the timing belt is lightweight and has a simple structure, there is a problem that the moving body falls when the timing belt is cut due to some abnormality. SUMMARY OF THE INVENTION An object of the present invention is to provide a belt drive traveling device which has a safety measure against the cutting of a timing belt and has a simple structure.

[0004]

According to the present invention, a fixed portion is provided with a pulley, two tension pulleys provided on both sides of the pulley, and a driving portion for rotating the pulley, and a guide provided on the fixed portion. In a belt drive traveling device in which an arm adapted to move along an arm is provided, both ends of the timing belt are attached to both ends of the arm, and the intermediate portion of the timing belt is wound around the pulley and the tension pulley. Both ends of the two timing belts provided in parallel with each other are attached to the side plate provided in
An abnormality detecting device for detecting an abnormality of the timing belt is provided on the side plate. Further, the abnormality detection device is configured by a photoelectric sensor in which a light emitting element and a light receiving element are arranged so as to sandwich the timing belt, or a plurality of integrally formed on the timing belt and connected in series at both ends. It comprises a steel cord and a current detecting device for detecting a weak current flowing through the steel cords connected in series.

[0005]

[Function] Even if one of the two belts is damaged,
The abnormality detection device detects the breakage of the timing belt and issues an alarm to notify the abnormality to perform maintenance work.
In this case, the moving part such as the arm is maintained in its current state by the undamaged timing belt, so that safety is ensured. Further, even if one of the timing belts is broken, the position of the arm does not change, so it is not necessary to correct the position information for controlling the arm.

[0006]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 (a) is a side view showing an embodiment of the present invention, and FIG. 2 (b).
In its front view, a pulley 2 is fixed to a fixed portion 1, two tension pulleys 3 are provided on both sides of the pulley 2, and a drive portion 4 having a drive motor for rotating the pulley 2 is fixed. Also,
The fixed portion 1 is provided with a guide 11, an arm 5 having a linear slide surface 51 adapted to move along the guide 11 is provided, and side plates 52 provided at both ends of the arm 5 are provided with rack teeth. Both ends of two timing belts 6, 6 provided in parallel with each other are attached, and intermediate portions of the timing belts 6, 6 are respectively wound around a pulley 2 and a tension pulley 3. As for the two timing belts, one having sufficient strength against a normal load is used. The side plate 52 is provided with an abnormality detecting device such as a photoelectric sensor 7 in which a light emitting element and a light receiving element are arranged so as to sandwich the two timing belts 6 therebetween. Even if an abnormality such as a load or meshing of the timing belt 6 occurs during long-term use with such a configuration,
The probability that the book's timing belt will be damaged at the same time is close to zero. However, in the worst case, when one belt is damaged, the photoelectric sensor 7 detects the damage of the timing belt 6 and issues an alarm to notify the abnormality to perform maintenance work. In this case, the moving part such as the arm 5 is maintained in its current state by the undamaged timing belt 6, so that safety is ensured. Further, even if one timing belt 6 is damaged, the position of the arm 5 does not change, so it is not necessary to correct the position information for controlling the arm 5. The abnormality detecting device may be a limit switch in which the timing belt is brought into contact with the belt by applying a preload. Since the timing belt 6 is under tension, the pressure of the limit switch becomes zero when it is damaged, and the abnormality can be detected.

FIG. 3 (a) is a front view showing another embodiment of the abnormality detecting device, in which a steel cord for enhancing the strength in the longitudinal direction of the timing belt 6 is integrally molded with rubber as a core wire. Then, as shown in the configuration diagram in FIG. 3B, the steel cords 61 are connected at both ends so that the plurality of steel cords 61 provided in the timing belt 6 are in series, and the steel cords 61 are connected in series. A current detecting device 8 for detecting a weak current by flowing a weak current through the steel cord is connected. Therefore, if the timing belt 6 is broken due to an abnormality, the steel cord 61 is broken.
Since the current detector 8 is also broken, the current detecting device 8 detects the abnormality when the weak current becomes zero. Although several tens of steel cords are normally put in the timing belt, all the steel cords may not be connected in series, but may be connected in series for every several evenly arranged steel cords. In addition, the tension of both timing belts and the current value of the weak current are adjusted to be the same, and the values of the weak currents of the two timing belts during long-term use are compared so that the tension changes. The change in the resistance value caused by the above may be obtained from the difference between the two current values, and the abnormality in the tension of the timing belt may be predicted before it is broken.

[0008]

As described above, according to the present invention, by providing two timing belts, even if an abnormality occurs in one timing belt, maintenance work can be performed without seriously affecting the entire traveling device. Therefore, there is an effect that it is possible to provide a belt drive traveling device which is lightweight and has a simple structure while ensuring safety against breakage of the timing belt.

[Brief description of drawings]

FIG. 1 (a) is a side view showing an embodiment of the present invention.

FIG. 1 (b) is a front view showing an embodiment of the present invention.

FIG. 2 (a) is a side view showing another embodiment of the present invention.

FIG. 2B is a configuration diagram of an abnormality detection device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Fixed Part 2 Pulley 3 Tension Pulley 4 Drive Part 5 Arm 6 Timing Belt 7 Photoelectric Sensor 8 Current Detection Device

Claims (3)

[Scope of utility model registration request] 1. A fixed portion is provided with a pulley, two tension pulleys provided on both sides of the pulley, and a driving portion for rotating the pulley, and the movable portion is moved along a guide provided on the fixed portion. In a belt drive traveling device in which an arm is provided, both ends of the timing belt are attached to both ends of the arm, and the intermediate portion of the timing belt is wound around the pulley and the tension pulley, two side plates are provided on both side plates of the arm. A belt drive traveling device, wherein both ends of the timing belts provided in parallel with each other are attached, and an abnormality detection device for detecting an abnormality of the timing belts is provided on the side plate. 2. The belt drive traveling device according to claim 1, wherein the abnormality detection device is composed of a photoelectric sensor in which a light emitting element and a light receiving element are arranged so as to sandwich the timing belt. 3. The abnormality detecting device detects a plurality of steel cords integrally formed with the timing belt and connected in series at both ends, and a weak current flowing through the steel cords connected in series. The belt drive traveling device according to claim 1, wherein the belt drive traveling device comprises a current detecting device.