JPH0726249Y2 - Safety equipment on work line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to improvement of a safety device in a work line.

(Prior Art) Conventionally, for example, when painting the bodies of a plurality of vehicles such as automobiles at a painting line in a vehicle assembly plant, the bodies are placed on a conveyor such as a belt conveyor and the painting area of the painting line is After determining the type of each body by the photoelectric tube provided in the coating area, the coating gun such as a side gun and a top gun provided in the coating area is used to face each body. It is generally common to spray paint suitable for the body. And in this case, a safety fence is provided in the painting area,
From the time each body is carried into the painting area to the time the painting is completed and is carried out from the painting area, the safety fence is closed to prevent an operator from unintentionally entering the painting area. Is designed to ensure the safety of.

However, even if the safety fence is provided as described above, the safety fence remains open until the finished body is unloaded from the painting area and the next body is loaded. It was very dangerous because a person could enter the painting area unexpectedly.

Therefore, limit switches are provided respectively in the front of the coating area in the transport direction and in the coating area, and after each body is transported to the work area and the limit switch on the front side in the transport direction is activated, If the photocell is interrupted before the limit switch is activated, the operator is considered to have entered the painting area and an alarm is issued to warn of an abnormal situation, and the drive of the conveyor is stopped to ensure worker safety. A safety device has been proposed that takes all possible measures.

(Problems to be solved by the invention) However, in the safety device of the above-mentioned proposal example, the limit switch is provided between the front of the painting area in the conveying direction and the interior of the painting area.
There was a problem that it had to be installed in a certain place, and it was expensive. Further, there is a problem that the limit switch in the coating area is apt to malfunction when paint adheres, which is not preferable from the viewpoint of ensuring worker's safety.

The present invention has been made in view of such a point, and its purpose is to ensure that the worker enters the above work area only by the limit switch on the front side in the transport direction of the work area such as the painting area. In order to reduce the cost by eliminating one limit switch, it is possible to eliminate the limit switch in the work area by taking appropriate measures that can be detected. Furthermore, by eliminating the limit switch in the work area as described above, it is possible to prevent malfunction of the limit switch due to work and to further ensure worker safety.

(Means for Solving the Problem) In order to achieve the above object, the present invention places a plurality of workpieces on a conveyor and conveys them to a work area, and performs a predetermined work on each of the workpieces. For the safety devices in the work line, the following measures were taken.

That is, the solution means of the present invention provides a discrimination means for discriminating the presence or absence of an object in the work area. Further, a pulse transmitter for transmitting a pulse for each predetermined movement amount of the transport conveyor is provided in the drive section of the transport conveyor. Further, detection means for detecting that each of the workpieces has been conveyed to the front side of the work area is provided on the front side in the conveyance direction of the work area.
Further, while counting the number of pulses transmitted from the pulse generator based on the detection signal of the detection means, when the workpieces pass the position of the determination means in the work area, the counting of the pulses is stopped. A counter for counting the number of pulses corresponding to the type of work is provided.
In addition, the count value of the counter is stored while each of the workpieces passes the position of the determining means, and when the determining means operates within a range that deviates from the count value, the workpieces are placed in the work area. It is characterized in that a control means is provided for stopping the driving of the conveyer conveyor, assuming that an object other than the above has entered.

(Operation) With the above configuration, in the present invention, when a plurality of work objects are placed on the work line on the work conveyor and are carried to the front of the work area in the carrying direction, this is detected by the detection means, The counting of the pulses transmitted from the pulse generator provided in the drive section of the conveyor is started by the counter based on the detection signal of the above-mentioned detection means. After that, when each of the work pieces passes the position of the discriminating means in the work area, the counting of the pulses transmitted from the pulse transmitter is stopped, and the number of pulses corresponding to the type of the work piece is counted. Then, when the discrimination means operates within a range that deviates from the count value of the counter while the respective work objects pass the discrimination means position, it is considered that an object other than the work object has entered the work area. As a result, the drive of the transfer conveyor is stopped by the control means.

Therefore, it is possible to reliably detect that the worker or the like has entered the work area by providing the detection means only on the front side in the transport direction of the work area, and there is no need to provide a separate detection means in the work area. Therefore, the cost can be reduced accordingly. Further, by eliminating the detection means in the work area as described above, the malfunction of the limit switch caused by the work is eliminated, and the safety of the worker is further ensured.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a case where the safety device according to the embodiment of the present invention is applied to a coating line A as a work line in a vehicle assembly factory. In the figure, 1 is a painting area as a work area, 2 is
Are the bodies B, B, ... of automobiles as a plurality of work pieces (second
(Only one is shown in the figure) is a conveyor such as a belt conveyor for conveying to the coating area 1, and in the coating area 1, side guns 3 and 3 for coating the side surface of each body B, A top gun 4 for painting the top surface of each body B and a side gun 3 are provided.
The top gun 4 is adapted to spray paint on each of the bodies B.

Further, safety fences 5, 5 are provided on the upstream side (left side in FIG. 2) and the downstream side (right side in FIG. 2) of the coating area 1 in the conveying direction, and each body B is carried into the coating area 1. During the period from the completion of the coating to the completion of the coating and the removal from the coating area 1, the safety fences 5 are closed to prevent the operator from unintentionally entering the coating area 1 to improve the safety of the operator. It is designed to secure.

Further, inside the safety fence 5 on the upstream side in the transport direction, a pair of photoelectric tubes 6 and 6 are provided as discrimination means, and the presence or absence of an object is discriminated by the photoelectric cells 6 and 6. When a plurality of bodies B, B, ... Are to be coated in the coating line A, each body B is placed on the transport conveyor 2 and transported to the coating area 1 so that the photoelectric tubes 6, which are upstream in the transport direction, The presence / absence of an object is discriminated at 6 and when the object is a body B, B, ... Of an automobile, the side guns 3 and 3 and the top gun 4 are directed to each body B depending on the type of each body B. The paint suitable for each body B is sprayed.

Further, as shown in the control block diagram of FIG. 1, a pulse transmitter 7 is arranged on a drive shaft 2a as a drive unit of the conveyor 2 and the pulse transmitter 7 moves the conveyor 2 in a predetermined manner. A pulse (conveyor pulse) as shown in the timing chart of FIG. 3 is transmitted for each amount.

Further, a limit switch 8 as detection means connected to a counter 9 which will be described later is arranged in front of the coating area 1 in the conveying direction (on the left side in FIG. 2), and each of the bodies B is coated by the limit switch 8. The fact that the paper has been conveyed to the front of the area 1 is detected, and this detection signal is output to the counter 9.

Further, the pulse transmitter 7 is connected to a counter 9, and the counter 9 transmits the pulse by inputting a reset pulse for each conveyance pitch (Tmax) of the body B as shown in the timing chart of FIG. The pulse transmitted from the device 7 is counted 0 to Tmax times. That is, the counter 9 starts counting the pulses transmitted from the pulse transmitter 7 based on the detection signal of the limit switch 8, while each body B passes the positions of the photoelectric tubes 6 and 6 in the painting area 1. Then, the counting of the pulses is stopped and the number of pulses corresponding to the type of the body B is counted. That is, each body B
The limit switch 8 is activated by the passage of the
Since the body shape varies depending on the type of vehicle when the vehicle operates, the number of pulses counted during this time shows a different value for each type of vehicle (body B), and the type of vehicle can be determined accordingly. .

Further, the photoelectric tubes 6 and 6 and the counter 9 on the upstream side in the carrying direction are input and connected to a control device 10 as control means,
The control device 10 is adapted to store the count value (a _{1 to} a ₂ ) of the counter 9 while each body B passes through the positions of the photocells 6 and 6, that is, the vehicle length. During this time, the phototubes 6, 6 on the upstream side in the transport direction stop the detection function, and after the body B passes (the limit switch 8
When the count corresponding to the vehicle length is reached from the time of operation), the detection function is restored.

A pair of photocells 6,6 are also provided inside the safety fence 5 on the downstream side in the transport direction. The photocells 6,6 are pulsed while the body B passes through the photocells 6,6 on the upstream side in the transport direction. The detection function of the photocells 6, 6 is stopped based on the count value of the number, that is, for the vehicle length corresponding to the vehicle type.

Further, the control device 10 is connected to the drive shaft 2a of the transfer conveyor 2 and the alarm device 11, and the count value (a ₁
Range departing from the _{~a 2) (a 1> T} ≧ 0 or a ₂ <T ≦ Tmax)
When the photoelectric tubes 6 and 6 are activated, the drive of the transfer conveyor 2 is stopped so that the transfer of each body B is stopped. That is, if the photocells 6 and 6 are blocked in the regions shown by hatching in FIG. 3 (regions where each body B does not block the photocells 6 and 6), an object other than the body B in the painting area 1, that is, a worker And so on,
The alarm device 11 is activated to warn of an abnormal situation, and the drive of the drive shaft 2a of the conveyor 2 is stopped. Even if an operator or the like enters the coating area 1 as described above, since the pulse count value according to the type of the body B is determined as described above, it is not affected by the intrusion of the operator or the like. , The pulse count value does not change. Therefore, the safety device according to the embodiment of the present invention is constituted by the pulse transmitter 7, the limit switch 8, the counter 9, the control device 10, the alarm device 11 and the like.
Twelve are made up.

As described above, in the present embodiment, a plurality of bodies B, B, ... Are placed on the conveyor 2 and conveyed to the front in the conveying direction of the coating area 1 of the coating line A, and this is detected by the limit switch 8. The drive shaft 2a of the transfer conveyor 2
The counter 9 starts counting the pulses transmitted from the pulse transmitter 7 provided on the basis of the detection signal from the limit switch 8. After that, each body B is carried into the coating area 1, and when each body B passes the position of the photoelectric tubes 6 and 6 in the coating area 1, the counting of the pulses transmitted from the pulse transmitter 7 is stopped. .
Then, when the photoelectric tubes 6 and 6 operate within a range that deviates from the count value of the counter 9 while each body B passes through the positions of the photoelectric tubes 6 and 6, a worker or the like enters the painting area 1. Then, the drive of the conveyor 2 is stopped by the controller 10.

Therefore, an operator or the like can simply set the limit switch 8 only on the front side of the coating area 1 in the conveying direction.
It is possible to reliably detect the entry into the interior, and thus it is not necessary to separately provide the limit switch 8 in the coating area 1, so that the cost can be reduced accordingly. Furthermore, by eliminating the limit switch 8 in the coating area 1 as described above, it is possible to prevent malfunction of the limit switch due to painting work and to further ensure the safety of workers and the like.

Further, in the above-described embodiment, in the multi-vehicle mixed flow line, compared to the case where the limit switches are arranged at two positions in the front of the coating area 1 in the conveying direction and in the coating area 1 as in the conventional example, a mesh is added to FIG. This has the advantage that safety can be secured in the area indicated by. That is, in the conventional example, since the limit switches 8 and 8 must be arranged according to the maximum body B length, the worker intrusion detection area (abnormal situation detection area) is the same regardless of the change of the vehicle type. In the embodiment, the worker intrusion detection area (abnormal situation detection area) can be set according to the change of the vehicle type. Therefore, in a vehicle type with a short body B length, only a portion corresponding to the short body B length can be set. An extra worker intrusion detection area (abnormal situation detection area), that is, a safety area can be secured. That is, the photocells 6 and 6 can be operated except when passing through the photocells 6 and 6 of the body B. This is related to the vehicle length depending on the vehicle type.
The operating range of the
The operating range of 6 and 6 becomes longer.

In addition, in the above-mentioned embodiment, the case where it is applied to the coating line A is shown, but it is needless to say that it is not limited to this and can be applied to various work lines.

Further, in the above embodiment, the limit switch 8 is used as the detection means, but a proximity switch or the like may be used.

(Effects of the Invention) As described above, according to the present invention, the count of the pulses transmitted from the pulse transmitter provided in the drive unit of the conveyor for conveying a plurality of workpieces is transferred to the work area. While starting based on the detection signal of the detection means provided in the front of the direction, when each of the above-mentioned work objects passes the position of the judgment means in the work area, the counting of the above pulses is stopped, and a pulse corresponding to the type of work object Try to count the number. Further, when the discrimination means operates in a range that deviates from the count value of the counter while each of the work objects passes the discrimination means position, it is considered that an object other than the work object has entered the work area. The driving of the transfer conveyor is stopped. Therefore, the detection means in the work area can be eliminated, and the cost can be reduced accordingly. Furthermore, by eliminating the detection means in the work area as described above, malfunction of the detection means due to work can be eliminated, and the safety of the worker can be further ensured.

[Brief description of drawings]

FIG. 1 is a control block diagram of a safety device according to an embodiment of the present invention, FIG. 2 is a configuration diagram schematically showing a coating area of a coating line, and FIG. 3 is a pulse transmitted from a pulse transmitter and an operator. FIG. 6 is a timing chart showing a positional relationship between an intrusion detection area and a vehicle type. 1 ... Painting area (working area) 2 ... Conveyor 2a ... Drive shaft (driving section) 6 ... Photoelectric tube (discriminating means) 7 ... Pulse transmitter 8 ... Limit switch (detecting means) 9 ... Counter 10: Control device (control means) 12: Safety device A: Painting line (work line) B: Body (workpiece)

Claims (1)

[Scope of utility model registration request] 1. A safety device in a work line for mounting a plurality of work objects on a conveyor to convey the work objects to a work area, and performing a predetermined work on each work object, the safety device being provided in the work area. A discriminating means for discriminating the presence / absence of an object, a pulse transmitter provided in the drive section of the conveyer conveyor for transmitting a pulse for each predetermined movement amount of the conveyer, and provided in front of the work area in the conveying direction, The detection means for detecting that each work is conveyed to the front of the work area, and the counting of the pulses transmitted from the pulse transmitter based on the detection signal of the detection means is started, while the work is When the pulse passes the position of the discrimination means in the work area, the counting of the pulses is stopped, and the counter that counts the number of pulses corresponding to the type of the work piece and the work pieces The count value of the counter is stored while passing through the position of the discriminating means, and when the discriminating means operates within a range deviating from the count value, it is considered that an object other than the work piece has entered the work area. A safety device in a work line, comprising: a control unit that stops driving of the transfer conveyor.