JPH07251914A - Article conveying method - Google Patents

Abstract

PURPOSE:To provide an article-conveying method by which a part mounted, for instance, on a circuit substrate or the like is prevented from being fallen, inexpensively and in a simple control method. CONSTITUTION:An article-conveying method is provided with a first process for conveying a circuit substrate P by supplying power to a motor for driving conveying belts 2a, 2b, a second process for stopping the power supply to the motor when the circuit substrate P reaches a point before a target position as much as a prescribed distance l, a third process for again supplying power to the motor after a prescribed time from the stoppage of the supplying power to the motor, and consequently from the stoppage of the conveying belts 2a, 2b, and a fourth process for stopping the supply of power to the motor after the circuit substrate P has abutted on a stopper 8 that has beed arranged in a target position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article carrying method for carrying articles by a belt, and more particularly to an article carrying method for carrying electric parts such as circuit boards.

[0002]

2. Description of the Related Art Conventionally, when a printed circuit board or the like is placed on a conveyor belt or the like and conveyed, there has been a problem that a component on the board collapses due to an impact when the conveyor belt stops.

In order to solve this problem, as disclosed in, for example, Japanese Patent Application Laid-Open No. 4-299898,
Techniques have been proposed for preventing the parts from collapsing by optimally controlling the acceleration / deceleration pattern of the conveyor belt.

[0004]

However, the above-mentioned conventional example has the following problems. (1) Since a servo motor, a stepping motor, or the like is used as a drive motor, it is more expensive than when an induction motor is used as the motor and control device. (2) In order to optimize the acceleration / deceleration pattern, the acceleration / deceleration pattern is changed by trial and error to find a pattern in which the parts do not fall down, so that it takes time and effort to set the optimum state.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to inexpensively
Another object of the present invention is to provide a method for conveying an article that prevents components mounted on, for example, a circuit board from falling over with a simple control method.

[0006]

In order to solve the above-mentioned problems and achieve the object, an article conveying method of the present invention is to convey an article to a predetermined target position by a conveyor belt driven by a motor. A first step of supplying an electric power to the motor to drive the conveyance belt to convey the article, which is a method of conveying the article to a target position.
A second step of stopping power supply to the motor when the article reaches a predetermined distance before the target position, and a predetermined time after the power supply to the motor is stopped and the conveyor belt is stopped. And a fourth step of stopping the power supply to the motor after the article comes into contact with the stopper arranged at the target position. Is characterized by.

Further, in the article conveying method according to the present invention, in the first step and the third step, when supplying electric power to the motor, a constant voltage is applied to the motor.

Further, in the article conveying method according to the present invention, the constant voltage is a voltage required to move the conveying belt at the constant speed.

Further, the article conveying method according to the present invention is characterized in that the first optical sensor detects that the article has reached a predetermined distance from the target position.

Further, in the article conveying method according to the present invention, it is the second step that the article comes into contact with the stopper.
Is detected by the optical sensor of.

Further, in the article conveying method according to the present invention, in the fourth step, substantially simultaneously with the detection of the contact of the article by the second optical sensor with the motor, It is characterized by stopping the power supply of.

Further, the article conveying method according to the present invention is characterized in that a material having a small friction coefficient is used for the conveying belt.

[0013]

As described above, since the article conveying method according to the present invention is configured, the feeding belt is moved at a constant speed, and when the article reaches the target position by a predetermined distance, power is supplied to the motor. By stopping, the conveyor belt stops at a substantially constant acceleration. At this time, the conveyor belt stops gently and the article stops while sliding with respect to the belt. Therefore, the acceleration applied to the article is small, and if the article is, for example, a circuit board, the parts mounted on the circuit board are It is prevented from falling. Further, when the article is stopped, the article comes immediately before the target position, so even when the conveyor belt is driven again and the article abuts against the stopper, the movement distance at this time is small, so the conveyor belt is The speed is still slow and the impact when the article hits the stopper is small. Furthermore, when the conveyor belt accelerates, the article slips with respect to the conveyor belt, so that the acceleration of the article becomes smaller than the acceleration of the belt, so that the impact when the article hits the stopper becomes smaller. Therefore, it is possible to prevent the components mounted on the article such as the circuit board from falling down.

When power is supplied to the motor,
A constant voltage is applied to accelerate linearly, and when stopping the motor, the power supply is simply stopped, so the control and control circuit of the motor is simplified and the cost is reduced. You can Even in this case, since slippage occurs between the article and the conveyor belt, the acceleration applied to the article is smaller than the acceleration of deceleration of the conveyor belt, and the impact applied to the article is mitigated.

Such an effect is further enhanced by using a material having a small friction coefficient for the conveyor belt.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2 are plan views showing the construction of an embodiment of an article conveying apparatus to which the article conveying method of the present invention is applied, and FIGS. 3 and 4 are side views of FIG. FIG. 5 is a sectional view taken along line AA of FIG.

1 to 5, reference numerals 1a and 1b are guide rods, and belts 2a and 2b are provided respectively. The belts 2a and 2b are induction motors 3a and 3b, respectively.
It is driven by 3b. Then, the printed circuit board P as an article to be conveyed has the belts 2a and 2b as shown in FIG.
It is mounted on and transported.

4, 5, 6 and 7 are substrate detection sensors,
It is for detecting the printed circuit board P conveyed by the belts 2a and 2b.

Numerals 8, 9 and 10 are stoppers composed of cylinders, which serve to stop the conveyed printed circuit board P at a target position.

Numerals 11 and 12 are positioning pins, which are positioned in the positioning holes H1 and H2 provided in the printed board P to position the printed board P.

The positioning pins 11 and 12 are fixed to the base plate 13, and the shafts 14 and 15 are fixed to the base plate 13. Shaft 1
4 and 15 are guide bushes 17 fixed to the pedestal 16,
18 is slidably supported. Ie pin 1
The reference numerals 1 and 12 are supported together with the base plate 13 so as to be vertically movable with respect to the pedestal 16.

The rod of the cylinder 19 fixed to the frame 16 is fixed to the base plate 13. As a result, by the push-out operation of the rod of the cylinder 19, the positioning pins 11 and 12 can move forward and backward in the positioning holes H1 and H2 of the printed circuit board P, respectively.

Next, the operation of conveying the printed circuit board P will be described with reference to FIGS. 7 and 8. FIG. 7 shows the motor 3a,
3 shows the relationship between the speeds of the belts 2a and 2b (in the figure) and the speed of the printed circuit board P (in the figure) when rotating 3b. The motors 3a and 3b have belts 2a,
A constant voltage required for moving 2b at the speed V is applied, and the belts 2a and 2b are accelerated to the speed V at a constant acceleration. At the start of rotation of the motors 3a and 3b, the belt 2
Since slippage occurs between a and 2b and the printed circuit board P, the speed of the printed circuit board P does not follow the speed of the belts 2a and 2b. After that, the slip decreases and the same speed V
become. When the motor rotation stop command is issued, the motor 3a,
The power supply to 3b is stopped, and the belts 2a and 2b are decelerated at a substantially constant acceleration. Also at this time, slippage occurs between the belts 2a and 2b and the printed circuit board P, and the printed circuit board P
Stops after the belts 2a and 2b.

In FIG. 8, 5'and 6'indicate the optical axes of the substrate detection sensors 5 and 6, respectively. The sensor 6 is installed in front of the position of the stopper 8 which is the target stop position of the substrate P by a distance l. The method of setting l will be described later.

First, in (a), when the substrate P is detected by the sensor 6, the power supply to the motors 3a and 3b is stopped. Then, as described above, the belts 2a and 2b are
Decelerates at a substantially constant acceleration, and the substrate P moves toward the belt 2a,
With respect to 2b, the speed is reduced while slipping, and the state of (b) is obtained. Due to the movement of the belts 2a and 2b during deceleration and the slip of the substrate P, the substrate P is displaced from the position of the sensor 6 by Δx. The value of Δx is set to be slightly smaller than the distance l. Since the value of the distance Δx naturally varies, the value of Δx may be larger than the distance 1 in some cases, and the substrate P may collide with the stopper 8. However, even if the board P collides with the stopper 8, since the board P is almost in a stopped state, the speed is slow and the parts on the board P do not fall.
The setting method of l is set to the shortest distance within the range in which the components on the substrate do not fall down even if such a collision occurs. When the motors 3a and 3b are rotated again after a fixed time Δt,
As shown in (c), the substrate P contacts the stopper 8.
Also in this case, as described above, when the motor starts rotating, the substrate P moves at a speed lower than the speed of the belts 2a and 2b due to the slip.
The upper parts do not fall. Then, the sensor 5 detects that the substrate P has come into contact with the stopper 8, the motor is stopped, and the rod of the cylinder 19 is pushed out to operate the positioning pins 11 and 12 as shown in (d). It is inserted into the positioning holes H1 and H2 of P.

After that, the rod of the stopper 8 is retracted as shown in (e). As a result, the substrate P is positioned at the target position.

When the coefficient of friction between the belts 2a and 2b and the substrate P is 0.1, the velocity V of the belt is 400 mm / s, and the weight of the substrate P is 1 Kgw, Δt = 0.1 (s), l = 40 to 50
By setting it to (mm), it was possible to prevent the parts from collapsing during a collision.

The positional relationship between the stopper 9 and the optical axis 7'of the sensor 7 is also configured to be separated by l.
When the substrate P is detected by, the power supply to the motors 3a and 3b is stopped. Therefore, as described above, even if the substrate P collides with the stopper 9 due to the large amount of slip, the impact force is small and the components on the substrate P do not fall. Also, the motors 3a and 3b rotate again,
Even if the belts 2a and 2b move, as described above,
Even if the substrate P collides with the stopper 9, the impact force is small and the components on the substrate P do not fall.

When the board P is positioned by the positioning pins 11 and 12 by the procedure described above, the board P is
On the other hand, components supplied from a known supply device (a parts feeder, a tray feeder, a stick feeder, etc.) by a known robot are mounted.

The board P, which has been mounted, has positioning pins 1
After removing 1, 12 and lowering the stopper 8, the motor 3
By rotating a and 3b, they are conveyed by belts 2a and 2b. In addition, the board whose movement is restricted by the stopper 9 lowers the stopper 9 to move the motors 3a and 3b.
Is rotated and conveyed by the belts 2a and 2b, and is positioned and mounted by the above-described operation. Substrates are sequentially supplied onto the belts 2a and 2b by hand or a substrate supply device (not shown) or the like, and are mounted by the above-described operation.

As described above, according to the above-described embodiment, the feeding belt is moved at a constant speed, and when the substrate reaches the target position by the predetermined distance, the power supply to the motor is stopped. The conveyor belt stops at a substantially constant acceleration. At this time, the conveyor belt stops gently and the board stops while sliding with respect to the belt. Therefore, the acceleration applied to the board is small and the components mounted on the circuit board are prevented from falling. Further, when the substrate is stopped, the substrate is located immediately before the target position.Therefore, even when the transport belt is driven again and the substrate is abutted against the stopper, the transport distance at this time is small, so the transport belt is The speed is still slow, and the impact when the board hits the stopper is small. Further, when the transport belt accelerates, the substrate slides with respect to the transport belt, so that the acceleration of the substrate becomes smaller than the acceleration of the belt, so that the impact when the substrate hits the stopper becomes smaller. Therefore, the components mounted on the board can be prevented from falling.

When supplying electric power to the motor,
A constant voltage is applied to accelerate linearly, and when stopping the motor, the power supply is simply stopped, so the control and control circuit of the motor is simplified and the cost is reduced. You can Even in this case, since slippage occurs between the substrate and the conveyor belt, the acceleration applied to the substrate is smaller than the acceleration of deceleration of the conveyor belt, and the impact applied to the substrate is mitigated.

Such an effect is further enhanced by using a material having a small friction coefficient for the conveyor belt.

The present invention can be applied to a modified or modified version of the above embodiment without departing from the spirit of the invention.

For example, in the above embodiments, the case where the present invention is applied to the conveyance of the circuit board has been described, but it is needless to say that the present invention is not limited to this and can be widely applied to the conveyance of articles that are not susceptible to impact.

Although the optical sensor is used as the substrate detecting sensor, the sensor is not limited to the optical sensor, and any sensor that can detect the substrate in a non-contact manner may be used.

[0038]

As described above, according to the article conveying method of the present invention, the conveyor belt is moved at a constant speed, and when the article reaches the target position by a predetermined distance, the motor is powered. By stopping, the conveyor belt stops at a substantially constant acceleration. At this time, the conveyor belt stops gently and the article stops while sliding with respect to the belt. Therefore, the acceleration applied to the article is small, and if the article is, for example, a circuit board, the parts mounted on the circuit board are It is prevented from falling. Further, when the article is stopped, the article comes immediately before the target position, so even when the conveyor belt is driven again and the article abuts against the stopper, the movement distance at this time is small, so the conveyor belt is The speed is still slow and the impact when the article hits the stopper is small. Furthermore, when the conveyor belt accelerates, the article slips with respect to the conveyor belt, so that the acceleration of the article becomes smaller than the acceleration of the belt, so that the impact when the article hits the stopper becomes smaller. Therefore, it is possible to prevent the components mounted on the article such as the circuit board from falling down.

When supplying electric power to the motor,
A constant voltage is applied to accelerate linearly, and when stopping the motor, the power supply is simply stopped, so the control and control circuit of the motor is simplified and the cost is reduced. You can Even in this case, since slippage occurs between the article and the conveyor belt, the acceleration applied to the article is smaller than the acceleration of deceleration of the conveyor belt, and the impact applied to the article is mitigated.

Such an action is further enhanced by using a material having a small friction coefficient for the conveyor belt.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of an embodiment of an article carrying device to which an article carrying method of the present invention is applied.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is a partially enlarged view of FIG.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a perspective view showing how a circuit board is conveyed.

FIG. 7 is a diagram showing the relationship between the speed of the belt when the motor is rotated and the speed of the printed circuit board P.

FIG. 8 is a diagram showing a procedure for positioning a circuit board.

[Explanation of symbols]

 1a, 1b Guide rod 2a, 2b Belt 3a, 3b Motor 4,5,6,7 Substrate detection sensor 8,9,10 Stopper 11,12 Positioning pin 13 Base plate 14,15 Shaft 16 Stand 17,18 Guide bush 19 Cylinder

Claims (7)

[Claims] 1. A method of transporting an article to a predetermined target position by a transport belt driven by a motor and positioning the article at the target position, the method including supplying electric power to the motor to drive the transport belt. Drive,
A first step of transporting the article; a second step of stopping the power supply to the motor when the article reaches a predetermined distance from the target position; and a second step of stopping the power supply to the motor. A third step of supplying electric power to the motor again after a lapse of a predetermined time after the conveyance belt stops, and supplying electric power to the motor after the article comes into contact with a stopper arranged at the target position. And a fourth step of stopping. 2. The article conveying method according to claim 1, wherein a constant voltage is applied to the motor in supplying electric power to the motor in the first step and the third step. 3. The article conveying method according to claim 2, wherein the constant voltage is a voltage required to move the conveyor belt at the constant speed. 4. The article conveying method according to claim 1, wherein the first optical sensor detects that the article has reached a predetermined distance from the target position. 5. The article conveying method according to claim 1, wherein the second optical sensor detects that the article comes into contact with the stopper. 6. In the fourth step, the power supply to the motor is stopped at substantially the same time as the second optical sensor detects that the article contacts the stopper. The method of transporting an article according to claim 5. 7. The article conveying method according to claim 1, wherein a material having a small friction coefficient is used for the conveying belt.