JP2523045B2 - Braking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device, for example, a braking device for stopping an article at a predetermined position when the article is transferred by a belt conveyor.

[Conventional technology]

FIG. 6 shows a procedure for conveying articles by the belt conveyor.

A driven sprocket wheel 53 is provided on a drive shaft 52 to which a drive pulley 51 for winding a conveyor belt 50 is attached, and a chain 56 is stretched between the driven sprocket wheel 55 attached to a motor 54. 57 is a tension gear for absorbing the slack of the chain 56. As the motor 54, a motor with a brake is used to transfer the conveyed product W in the arrow direction on the conveyor belt 50. When the conveyed product W reaches a predetermined position, the motor 54 is stopped and the brake is applied to brake. To do.

In this case, the drive pool 51 is over-rotated by the inertial force of the conveyed article W, the chain 56 is bent as shown by the dotted line 56a, and then the tension gear 57 is actuated to pull it in the opposite direction, and the drive pulley 51 is rotated in the reverse direction. Stop. However, the repulsive force by the tension gear 57 is generally weak, and therefore the stop position of the conveyed article W is not constant.

As a stopping means for a predetermined position which is generally used as a solution to this problem, a pulley (or a disc) is attached to the drive shaft 52, that is, the shaft to be braked, a brake shoe is installed oppositely, and the brake shoe is a pulley (or a disc). ) There is a friction brake system that stops by pressing.

In addition, a pair of cylinders (or discs) are equipped with pawls that engage with the opposite surfaces, and one cylinder (or disc) is attached to the braked shaft, and both pawls are meshed to rotate the braked shaft. There is a system by a meshing clutch that stops the.

Further, as another means, a Geneva method is used, and a driven gear having pin grooves provided at equal intervals in the radial direction is attached to the braked shaft, and a pin to be fitted into the pin groove is provided in a projecting manner in the radial direction. There is a method of intermittently rotating and stopping the braked shaft by a predetermined angle by rotation.

Other than that, for example, a system using an electromagnetic brake or an air brake has been tried.

[Problems to be Solved by the Invention]

The method using the friction brake has a problem that the stop position of an article conveyed by a conveyor or the like is not constant due to inertial force, friction of a brake shoe, or the like.

In the case of the dog clutch system, the pawl pitch has a considerable length in order to give the pawl strength.
Therefore, there is a problem that the stop position does not stop at a predetermined position due to the displacement of one claw.

In addition, braking suddenly stopped due to meshing, damaging the device,
Alternatively, there is a problem that the conveyed product on the conveyor belt moves due to inertial force and does not stop at a predetermined position.

Further, in the Geneva method, the rotation angle of the braked shaft is constant, and it is difficult to freely change the rotation angle.

Further, since the electromagnetic braking method, that is, the braking by the electromagnetic force is accompanied by abrupt braking, the inertial force is large before and after the brake, which may damage the device, and there is a drawback that the conveyed object moves due to the inertial force.

In view of this point, the present invention has an object to provide a braking device capable of accurately stopping at a predetermined position by absorbing inertial force during braking.

[Means for solving the problem]

In order to achieve the above-mentioned object, the braking device of the present invention includes a rotating braking shaft, a guide surface on which the distance from the shaft center of the braking shaft is gradually reduced, and a bottom part on which the distance from the shaft center is minimum. , A cam having a braking surface that sequentially increases in distance from the shaft center is formed on the peripheral surface in order, and the cam can be retracted by an air cylinder so as to face the peripheral surface of the cam. A roller having a small radius of curvature is provided, and the roller is moved forward with respect to the cam while being brought into contact with the guide surface of the cam by the air cylinder, and the roller is retracted against the pressing force of the air cylinder by the braking surface of the cam. Thus, the inertial rotation of the braked shaft is prevented.

In this case, the air cylinder preferably includes supply pressure air adjusting means for adjusting the pressing force.

Further, it is desirable that the air cylinder includes a tuning means that operates when the roller faces a predetermined position of the cam in synchronization with the rotation of the cam.

[Action]

During braking, the roller is advanced by the air cylinder while contacting the guide surface of the cam. The roller passes from the guide surface of the cam past the bottom to the braking surface.

Then, the braking surface of the cam causes the roller to retreat against the pressing force of the air cylinder to prevent inertial rotation of the braked shaft, whereby the braked shaft is stopped in a buffer manner.

Further, when the supply pressure air adjusting means is provided in the air cylinder, it is possible to arbitrarily adjust the turning angle for buffering.

Further, when the air cylinder is provided with the tuning means, the roller can be advanced when the roller faces the most suitable position of the cam.

〔Example〕

 The figures show an embodiment of the invention.

The braking device 1 includes a cam 3 attached to the braked shaft 2,
A roller 4 is provided opposite to the cam 3. Laura 4
Is attached to the tip of an arm 6 whose one end is supported by a support shaft 5, and an air cylinder 7 is connected to the arm 6 at an appropriate position.

The cam 3 has a plurality of, for example, three cam surfaces 10 formed on the outer circumference. As shown in FIG. 3, the cam surface 10 has a cam A with an arrow A.
Of the maximum radius (maximum distance from the axis of the braked shaft 2) and the minimum radius (minimum distance from the axis of the shaft 2 to be braked) in order to accept the intrusion of the roller 4 when rotating in the direction. A guide surface 10c that connects the bottom portion 10b and that gradually decreases in distance from the axis of the braked shaft 2, and a braking surface that is formed beyond the bottom portion 10b and that sequentially increases in distance from the axis of the braked shaft 2.
It consists of 10d. The braking surface 10d is, for example, a straight line, and the angle θ with the radius is appropriately selected. This angle θ serves to buffer the inertial rotation of the driven shaft 2 as will be described later.
The size of is determined experimentally. The braking surface 10d can also be formed into a curved surface which is gentle at first and gradually steep as shown by a chain line 10e.

In this case, as shown in FIG. 3, the roller 4 is smoothly contacted with the bottom portion 10b of the cam 3 so that the bottom portion 10b of the cam 3 is in contact.
The radius of curvature of is larger than that of the roller 4.

In FIGS. 1 and 2, 11 is a driven sprocket wheel attached to the hollow shaft 12 of the cam 3, and 13 is a lock member for fixing the hollow shaft 12 to the braked shaft 2. The lock member 13 allows the hollow shaft 12 to rotate by loosening it, and the cam 3 is fixed to the braked shaft 2 by rotating the cam 3 to an arbitrary position and fastening the lock member 13. 14
Indicates a mounting frame, which penetrates the driven shaft 2 and is rotatably supported by a bearing 15. 16 is a drive sprocket wheel, 17 is a chain.

Reference numeral 21 is a supply pressure air adjusting means provided in the pressure air supply circuit 20 of the air cylinder 7, which is provided to control the pressure on the air cylinder side and is constituted by a pressure reducing valve or the like. Reference numeral 22 is an opening / closing valve, which is normally closed and opened during braking to supply pressurized air to the air cylinder 7. The operation timing of the air cylinder 7 is preferably performed when the roller 4 faces the guide surface 10c. Therefore, for example, the opening / closing valve 22 is an electromagnetic opening / closing valve, and the position of the cam is electrically detected to open / close the opening / closing valve. A tuning means 25 is provided which operates.

 Next, the operating procedure will be described based on FIG.

As shown in FIG. 4A, the roller 4 is normally held at a retracted position outside the rotation locus 3a of the apex 10a of the cam 3.

When the apex 10a is crossed, the air cylinder 7 is operated to push out the roller 4 and bring it into contact with the cam 3. That is, when the roller 4 faces the guide surface 10c of the cam surface 10, the opening / closing valve 22 is opened to operate the air cylinder 7. As a result, FIG.
As shown in (d), the roller is on the guide surface 10c of the rotating cam.
It rotates in contact with (the control force still does not work due to the relationship of the contact surface).

Then, the drive source is turned off at a place beyond the bottom portion 10b shown in FIG. Here, the cam 3 starts inertial rotation. Laura 4
Comes into contact with the control surface 10d and is pushed back against the pressing force of the air cylinder 7 (the contact angle becomes large). At the same time, the action becomes a braking action, and finally the cam 3 stops.

During the angle α (see FIG. 3) between the time when the vehicle passes the bottom portion 10b and the time when the vehicle stops, the buffering movement occurs during braking, and the braking force gradually increases. This angle α is the angle θ of the braking surface 10d described above.
Alternatively, it relates to the pressing force of the air cylinder 7, that is, the supplied air pressure together with the shape. However, it is difficult to adjust the angle θ and the like during use, and therefore the supply pressure air adjusting means 21 adjusts the angle θ and the like.

Accordingly, the angle α is appropriately selected depending on the magnitude of the inertial force applied to the braked shaft 2, and the supply pressure air adjusting means 21 adjusts the air pressure to the air cylinder 7 to keep the predetermined stop position constant.

FIG. 5 shows an example in which the present invention is applied to a belt conveyor. The drive pulley 31 around which the conveyor belt 30 is wound is attached to the braked shaft 2 described above. The other structure is the same as described above.

In this case, when the conveyed article W approaches the predetermined stop position, the inertial force is absorbed and the conveyed article W accurately stops at the predetermined position.

〔The invention's effect〕

According to the present invention, since the cam is attached to the braked shaft and the roller is pressed against the cam by the air cylinder to bring it into contact with the cam surface at the time of braking, the braking can be surely and smoothly performed. In this case, the roller is moved forward with respect to the cam while being brought into contact with the guide surface of the cam by the air cylinder, and the roller is retracted against the pressing force of the air cylinder by the braking surface of the cam, whereby the air cylinder is moved to the shock absorber. And the braked shaft stops after the inertial force is absorbed. Therefore, when the present apparatus is applied to the belt conveyor, the transported object does not shift the stop position due to the inertial force.

Further, when the supply pressure air adjusting means is provided, it is effective for fine adjustment of the stop position.

Further, when the tuning means is provided, it is possible to prevent the pushed roller from immediately contacting the braking surface, which is effective in preventing malfunction.

[Brief description of drawings]

1 to 5 relate to an embodiment of the present invention, FIG. 1 is a front view of a braking device, FIG. 2 is a sectional view taken along the line I--I in FIG. 1, and FIG. 3 is a detail of a cam surface. Explanatory drawing, FIG. 4 is an operational explanatory drawing, FIG. 5 is an explanatory drawing in which the braking device of the present invention is applied to a belt conveyor, and FIG. 6 is an explanatory drawing of a conventional braking procedure. 1 is a braking device, 2 is a braked shaft, 3 is a cam, 4 is a roller,
7 is an air cylinder, 10 is a cam surface, 10b is a bottom portion, 10c is a guiding surface, 10d is a braking surface, 21 is a supply pressure air adjusting means, and 25 is a tuning means.

Claims (3)

(57) [Claims] Claim: What is claimed is: 1. A rotating braking shaft, a guide surface on which the distance from the shaft center of the braking shaft is gradually reduced, a bottom portion at which the distance from the shaft center is minimized, and a distance from the shaft center is sequentially increased. A cam having a braking surface to be formed on the peripheral surface is attached in order, and a roller having a radius of curvature smaller than the radius of curvature of the bottom portion of the cam is provided so as to face the peripheral surface of the cam and to be able to move forward and backward by an air cylinder. , The roller is moved forward with respect to the cam while being in contact with the guide surface of the cam by the air cylinder, and the roller is retracted against the pressing force of the air cylinder by the braking surface of the cam, thereby inertial rotation of the braked shaft. A braking device characterized by being designed to prevent 2. The braking device according to claim 1, wherein the air cylinder is provided with a supply pressure air adjusting means for adjusting a pressing force. 3. The braking device according to claim 1, wherein the air cylinder is provided with a tuning means that operates when the roller faces a predetermined position of the cam in synchronization with the rotation of the cam.