JP3197784B2 - Overload stop mechanism for shaft mounted motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload stop device for a shaft mount motor mounted on a drive shaft such as a chip conveyor, and when an overload acts on a conveyor drive shaft, the shaft end of the shaft is stopped. The present invention relates to a mechanism for operating an emergency stop switch of a supported drive motor.

[0002]

2. Description of the Related Art In a structure generally used in the prior art, as shown in FIG. 5, a motor 30 for driving a conveyor is disposed at a position distant from a driving sprocket shaft 2 of the conveyor. What is Chain 3
They are connected by 1 or a gear. In a chip conveyor or the like, chips (chips) may become entangled with the conveyor, and if the conveyor is forcibly driven in such a case, the device is broken. Therefore, a device is provided for stopping the conveyor when the conveyor is overloaded due to entanglement of the chips. As shown in FIG. 5, when a chain 31 and gears are provided in the drive system of the conveyor, a torque limiter 32 is provided in the rotation transmission mechanism so that when the conveyor 1 is overloaded, the rotation of the motor 30 is stopped. A mechanism that prevents transmission to the drive sprocket shaft 2 and detects the slip of the torque limiter 32 to stop the motor 30 in an emergency is employed.

In recent chip conveyors and the like, since the structure is simple and the apparatus can be manufactured at low cost, the drive sprocket shaft 2 of the conveyor is driven by a shaft mount motor 5 shown in FIG. 4 instead of the structure shown in FIG. Structures are being adopted. The shaft mount motor 5 is a motor having a built-in speed reducer, and a hollow shaft is used as its output shaft. The motor 5 is supported by fitting one end of the drive sprocket shaft 2 to the hollow shaft. An arm (torque arm) is fixed to the motor 5 to prevent rotation of the motor 5 itself due to the driving reaction force, and the swing of the arm is locked by a spring 16 or a stopper.

In such a structure using the shaft mount motor 5, since the motor and the driving sprocket shaft 2 are directly connected, a torque limiter cannot be provided therebetween.
A shaft mount motor having a built-in torque limiter in the motor is also provided, but is expensive. In addition, such a motor has a problem that it is difficult to detect when the shaft rotates while the torque limiter slides. Therefore, as shown in FIG.
When the torque arm 8 swings against the urging force of the spring 16 due to overload acting on the motor,
A structure is employed in which the swing is detected by the switch 19 and the motor 5 is stopped in an emergency.

[0005]

The driving torque of a standard chip conveyor used for an NC lathe or the like is 20 kgm.
It is about. In order to receive such a large amount of torque in the structure shown in FIG. 4, it is necessary to lengthen the torque arm 8 to a certain extent. Therefore, the spring 16 also becomes large, and the swing of the motor 5 when an overload is applied also becomes large. In addition, since the arm 8 moves, a cover for preventing danger is required, and there is a problem that the device becomes large. In particular, the torque arm 8 and the spring 16 for preventing its swing shown in FIG. 4 must be mounted so as to protrude to the side of the conveyor. There's a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has as its object to make a mechanism for detecting an overload of a shaft mount motor more compact.

[0007]

An overload detecting mechanism for a shaft-mounted motor according to the present invention comprises a motor 5 having one end of a driven shaft 2 fitted and fixed to a hollow output shaft 6 and a casing of the motor. A second arm 12 supported by a stationary member 3 by a support shaft 11 and a second arm 12 comprising: And a sensor 19 for detecting the swing of the tip 13 of the second arm 13 in the second direction. The spring 16 biases the first swing direction in the second swing direction. And the tip 10 of the torque arm 8 is in contact with an intermediate position of the second arm in a direction for pushing the second arm in the second direction. It is a feature. In the above configuration, it is advantageous that the support shaft 11 of the second arm 12 is located on a substantially extension of the torque arm 8, and the second arm 12 extends in a direction substantially opposite to the torque arm 8.

[0008]

The second arm 12 in the above configuration constitutes a mechanism for expanding the stroke by leverage. That is, the tip 10 of the torque arm 8 is in contact with an intermediate position of the second arm 12 and the switch 19 is
Since the second tip 13 is detected, the small swing stroke of the tip 10 of the torque arm is enlarged by the second arm 12 and detected by the switch 19. Also, since the stroke enlargement mechanism constitutes a force reduction mechanism at the same time,
By disposing the spring 16 near the tip of the second arm 12, the reaction force of the motor received by the spring 16 is reduced, and the size of the spring 16 can be reduced.

Since the stroke of the distal end is enlarged by the second arm 12, the arm length of the torque arm 8 can be shortened. Also for the second arm 12, if the distance from the support shaft center 11 to the position where the tip 10 of the first arm comes into contact is shorter than the arm length of the torque arm 8,
The overall length can be made shorter than the arm length of the torque arm in the conventional structure, so that the entire structure can be made more compact. In particular, according to the invention of claim 2, the torque arm 8
And the second arm 12 are turned back to make the device more compact,
Since the support shaft 11 of the arm is located away from the driven shaft 2, assembly and maintenance of the device are also facilitated.

[0010]

1 and 2 show a first embodiment of the present invention. Driving sprocket shaft 2 of chip conveyor 1
Are supported on the frame 3 by bearing blocks 4. The drive motor 5 of the chip conveyor is a motor having a built-in speed reducer. The output shaft 6 is a hollow shaft, and the motor 5 having one end of the drive sprocket shaft 2 fitted and fixed in the hollow hole 7 is supported. That is, the weight of the motor 5 is supported by the bearing block 4 via the drive sprocket shaft 2.

A torque arm 8 made of sheet metal is fixed to the motor 5 with a screw 9.
A roller 10 having an axis parallel to the drive sprocket shaft 2 is mounted.

A support shaft 11 is erected on the frame 3 of the chip conveyor in parallel with the drive sprocket shaft 2, and the base end of the second arm 12 is pivotally supported on the support shaft. Second
The arm 12 extends in a direction opposite to the torque arm 8, and a portion on the distal end side thereof crosses above the drive sprocket shaft 2. At the distal end 13 of the second arm 12, an adjustment bolt 14, which is adjustable in height in the vertical direction in the figure, is mounted. A spring seat 15 is formed at a substantially central portion of the second arm 12, and a compression coil spring 16 for urging the spring seat 15 upward is provided. Near the base end of the second arm 12, a catch 17 is provided at the bottom with a concave upper edge, and the roller 10 at the tip of the torque arm 8 contacts the upper surface of the catch 17. Below the distal end of the second arm 12, a limit switch 19 is mounted with the dog lever 18 facing the adjustment bolt 14.

The driving sprocket shaft 2 is driven clockwise in FIG. This driving reaction force acts to rotate the motor 5 counterclockwise in the figure, and the roller 10 at the tip of the torque arm 8 fixed to the motor 5 comes into contact with the catch 17 of the second arm 12, This is urged downward. This urging force is balanced by the compression coil spring 16, and the rotation of the motor 5 is prevented.

When an abnormal load acts on the chip conveyor 1, the output torque of the motor 5 increases, and the rotational reaction force applied to the motor 5 also increases. Therefore, the torque arm 8
The receiving metal 17 is pushed down with a stronger force, and the compression coil spring 16 is deformed to match the increase in the force. Due to this deformation, the second arm 12 swings clockwise in the figure, and pushes down the dog lever 18 of the limit switch 19. Therefore, an increase in the load torque of the chip conveyor 1 is detected by the limit switch 19.

FIG. 3 shows a main part of a second embodiment of the present invention. In the second embodiment, the second arm 12 extends in the same direction as the torque arm 8, and the distance L ₂ from the support shaft 11 of the second arm to the contact position of the roller 10 at the tip of the torque arm. It is shorter than the arm length L ₁ of the torque arm 8. By setting the arm length to the above relationship, the second arm 12 can be shortened, and the entire apparatus can be made compact.

[0016]

According to the present invention described above, the overload detecting mechanism of the shaft mount motor can be made compact.
Also, the amount of motor swing when overload is applied is small,
There is an effect that the spring receiving the reaction force of the motor can be reduced in size.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment.

FIG. 2 is a side view showing a relative relationship between arms.

FIG. 3 is a side view showing a relative relationship between arms according to a second embodiment.

FIG. 4 is an exploded perspective view showing a first conventional example.

FIG. 5 is an exploded perspective view showing a second conventional example.

[Explanation of symbols]

 2 Drive sprocket shaft 3 Frame 5 Motor 6 Motor output shaft 8 Torque arm 10 Roller 11 Support shaft 12 Second arm 13 End of second arm 16 Compression coil spring 19 Limit switch

Claims (2)

(57) [Claims] 1. A motor (5) supported by fitting and fixing one end of a driven shaft (2) to a hollow output shaft (6), and fixed to a casing of the motor to prevent rotation of the casing. In an overload detecting mechanism for a shaft mount motor having a torque arm (8), a second arm (12) supported by a stationary member (3) by a support shaft (11), and the second arm is connected to the second arm (12). A spring (16) for urging in the first swing direction, and a sensor (19) for detecting the swing of the tip (13) of the second arm in the second direction, wherein the first swing direction is provided. And the second direction are opposite to each other, and the tip (10) of the torque arm (8) is located at an intermediate position of the second arm in a direction for pushing the second arm in the second direction. An overload detection mechanism for a shaft-mounted motor, wherein the mechanism is in contact with the shaft. 2. The support shaft (11) of the second arm (12) is located on a substantially extension of the torque arm (8), and the second arm (12) is located in a direction substantially opposite to the torque arm (8). The overload detection mechanism for a shaft mounted motor according to claim 1, wherein the mechanism is extended.