JPS63174845A - Process skip preventing system - Google Patents

Abstract

PURPOSE:To perform a working job for each process to the incoming work without fail, by constituting a start of equipment for each process so as to be carried out only at a time when a starting signal out of a starting signal generating device at the previous process is being inputted. CONSTITUTION:After the work subjected to a working job at an n-1 process in advance of an optional (n) process is first set up in the (n) process, if a starting signal is generated at a starting signal generating device at the (n) process, a start of the (n) process is carried out because the starting signal of the preceding n-1 process is being generated. And, after the work is set up in equipment of the n process without passing through the preceding n-1 process, if the starting signal of the n process is generated, no start of the equipment of the n process is carried out because the starting signal of the preceding n-1 process is not generated. Therefore, if there is any process skip in the work to be conveyed to each process, it is easily findable at once at the adjacent process, so that the working job at respective processes is surely performed and, what is more, reliability in a product is improvable.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a method for preventing process skipping in order to prevent necessary machining or assembly processes for workpieces from being omitted in each process of a production line that has multiple processes. Regarding the method.

(Prior art) To process workpieces by sending them to a production line that requires a large amount of processing or assembly, one worker installs the workpieces in each piece of equipment, then performs processing on the workpieces.
Next, the worker removes the workpiece from the equipment, and then transfers the workpiece to the next process. At this time, workers may not check whether the equipment in each process is operating normally or forget to close the start switch of the equipment, etc.
Processing operations may not be performed on a workpiece in a certain process, resulting in a process omission.

Conventionally, when a product is completed on a production line, the finished product (product) has been visually checked using a gauge or the like. This results in
It is determined whether or not the workpiece has been processed or assembled correctly, and there is no check for process omissions.In addition, on an automatically operated production line, the workpieces sent to each process are not processed properly. Some devices emit an alarm when the workpiece is left installed on the mounting base without being properly installed, or when an attempt is made to start operating the equipment (closing the start switch) with the workpiece not installed properly. An example of this type of device is disclosed in Japanese Utility Model Publication No. 59-24440.

(Problems to be Solved by the Present Invention) However, when visually checking a finished product, process omissions may be found in machining operations similar to the external shape, but process omissions in processes other than the external shape may be discovered. Discovery takes time and effort. In addition, since inspection is not performed until the workpiece becomes a finished product, early detection of process omissions is difficult. As a result, there was a problem in that the reliability and productivity of the finished product could not be achieved.

Furthermore, the occurrence of process omissions is not continuous and is often due to human causes, making it extremely difficult to predict their occurrence.
Therefore, in order to obtain a product without any process omissions, it is necessary to check all the finished products, which poses a problem in that it requires a large amount of time and one worker.

The method disclosed in Japanese Utility Model Publication No. 59-24440 ensures that the workpieces sent (installed) to the process are processed reliably, but the workpieces are not processed in the previous process. It is not detected whether or not it has been applied. Therefore, detection and prevention of process skipping is not possible.

As a result, the present invention provides a process skipping prevention method that ensures that the machining work in each process in a production line is reliably carried out on the workpieces that arrive at each process.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a round start signal generating means for generating a start signal for starting the equipment in each process. The starting signal from the starting signal generating means is used to start the equipment of the process located next to each process when the starting signal from the starting signal generating means of the process located before the relevant process is input. This feature is characterized in that it is configured so that it is executed only when

(Function) Since the present invention is configured as described above, first, a workpiece that has been processed in a process before an arbitrary process is installed in the process, and then the start signal generating means of the process is used to start the process. When a start signal is generated, the start signal for the previous process is generated by the start signal generation means of the previous process, so the equipment of the process is started, and the start signal generation means of the process starts the equipment of the process. generates a start signal.

Furthermore, if the start signal for the process is generated by the start signal generation means for the process after the workpiece is installed in the equipment for the process without passing through the previous process, the start signal for the previous process will be Since the start signal has not been generated in the middle stage of generating the start signal, the start-up of the equipment in the process is not executed.

(Example) An example of the present invention will be described below in detail based on the drawings.

In FIG. 1, numeral 1 is a jitance circuit for preventing process skipping. This sequence circuit 1 mainly includes a limit switch (indicated by LS), a relay (indicated by CB), and a display 2. In the figure, X indicates a power line, and Y indicates a ground line. Note that relay contacts are indicated by adding an alphabet to the symbol of the relevant relay.

Limit switch LSI, relay CB1/CR2,
Contacts CB1a, IH-1, and a constitute a starting signal generating means that generates a starting signal indicating starting of the equipment in the nth step, shown in FIG. 2.This relay CRI
It is connected to the power supply line via the Fi limit switch L81, and when the limit switch LSI is closed, one relay CR,1 is energized and a start signal is generated. Contact CQ 1 a ij indicates a normally open contact of relay CRI. The contact 1H-1 is a select switch (not shown), which is normally closed while the production line is in operation. Contact a is a normally open contact of a setup switch (not shown) that closes after setup is completed in the n-th step. L/-CR2 is contact CR1
Since it is connected to the power line through atIH-1 and a, relay CR2 is connected to relay Ca during production line operation.
1 is energized, and is energized when the setup of the n-th step is completed.

Contact CR2a, Rev-CR3e Contact IH-2°C
R3a, C几4Jl, riv-CR4t'i said nth
This is for holding the generation of a process start signal. Contact CB2a is a normally open contact of relay CR2, and this contact CR
2a closes, relay CR3 connected to the power line via contact CR2a is energized. Contact 1H
-2 is a contact of a unit cycle start switch (not shown), and this contact is normally closed while the IH-2ki production line is in operation. Contact CR5a is a normally open contact of relay CR3, and is also a normally open contact of relay CR4.

Relay CB, 4 is contact 1H-2# CRs a LC
It is connected to the power supply line via the box 4a. As a result, the start signal for the nth process is sent to contact CR while the production line is in operation.
After closing 2a and energizing relay CR3, contact CR3
Close a. Next, relay CR4 has contacts IH-2, CR
Contact CR4a is closed because it is energized via CR3a. The subordinate terminal, V-CR4, is energized by the power line through contact 1H-2e CR4a, so relay C
Even if the excitation of R3 is released, the excitation of the relay CR4 is maintained, so the starting signal for the nth step is held.

Contacts C 5a, CR6a, C 4b, CR6b, relay CR6, and display device 2 constitute an alarm means, and display device 2 consists of a buzzer BZ and a lamp L. This alarm means is for displaying an alarm on the display device 2 to prevent the work from leaving the process if the start signal for the n-th process is generated when the start signal for the n-th process is not generated. The relay CB, 6 is connected to the power supply line via the normally open contact CR5a of the relay CB, 5, the normally open contact C of the relay CB, 5, and the normally closed contact CR4b of the relay CR4. When relay CR4 is energized - limit switch L
When S2 is closed, relay CR6 is not energized, but
If limit switch LS2 is closed while relay CR4 is not energized, relay CR6 is energized. The display device i12 is composed of a buzzer BZ and a second lamp L, a display device (l12 is connected to the power line via the normally open contact CR6b of relay CB and 6), and a relay CR16. With the excitation, the display device e2 warns and prevents process omissions. Thereafter, when limit switch LS2 is opened, relay CR6 also closes contact CR6a*C.
It is excited to 121g9in via R4b.

Contact point C 5b, CR4c, , C 7a, CR91°CB
3b, CR8a and v-CR,9 maintain the operating state of the equipment in the (n+1)th process.

Contact CR5b is the normally open contact of relay CR5, contact CR4c
is a normally open contact of relay CR4, and contact CR7a is a normally closed contact of a photoelectric switch (not shown). This photoelectric switch opens the contact point C and 1 when the lamp L of the display device 20 is turned on (vI notification signal).

Contact CR4d is the normally open contact of relay CR4 -〇, B 8
A is a normally open contact of a work confirmation switch, not shown. This workpiece confirmation switch closes contact CR8a after confirming the installation of the workpiece in the n+1 process.Relay CR9 has normally open contacts CR5b and CR4c.

CR8a, CB? a, CR3b and light t-X y f
(Connected to the power line via D normally closed contact CR7a. Contacts CR5c, CR7b, CB?b, Sv-C 1o
, CR5 and limit switch L82 are for starting the equipment for the (n+1)th process. Relay CR1G is connected to the power supply line via normally open contacts C5c and C9b and normally closed contact CR7b. Relay CB, 1
The contact G, which is not shown, controls the control device for starting the equipment for the 9hgn+1 process and the pilot lamp of the control device. Relay CBS is limit switch LS2
The switch L82, which is connected to the power supply line through the 9% limit, starts up the equipment for the B+1 process.

The operation of the device having the above configuration will be explained below.

First, the workpiece transported from the n-1st process (not shown)
After setting up the equipment for the nth process, the worker closes the limit switch LSI, which energizes the relay OR,1 and closes the contact CR1a. At this time, since the production line is in operation, the contact 1H-1 is closed, and since the setup for the n-1th process has been completed, the contact a is closed.

As a result, the equipment for the n-th process is started, and relay CR2 is energized and the contact (B2a is closed, so the equipment for the n-th process is activated.
A process activation signal is generated, and the nth process activation signal is transmitted to the (n+1)th process.

Then, as contact CR2a closes, relay C
Since B3 is excited, contact CB3a is closed. Here, contact 1H-2 is closed because the production line is in operation, so relay CR4 is energized. This results in
Since the contact CB4a is closed, even if the switch L81 is opened to de-energize the relay CR3, CB4 continues to be energized. Therefore, the confirmation signal for the %gn-1 process is stored in relay CR4. At the same time, the contact (Bsb) closes (described later).

Therefore, contact CR4b opens, so relay CB and 6Fi
Not encouraged. As a result, the display 5 does not operate. Further, the contact CR4c is closed (described later).

Next, after installing the workpiece in the (n+1)th process, the worker closes the limit switch LS2, and the relay CB5 is energized. As a result, contacts (!R5a, C-box 5b, and C-box 5c are closed, and contact CR8a is closed.

This causes relay CR9 to be energized.

Since contacts CB9a and C9b are closed, relay CR10
is energized and relay CR? Or limit switch L8
Even if relay Ca5 is deenergized by opening 2, relay CB9 continues to be energized because the contact (Job) is closed. Light up the pilot rung shown.

-1. If the workpiece does not pass through the nth process, but is installed in the n+1st process and the equipment for the n+1th process is started, the first worker does not close the 4nth process (cut switch L81 is not closed, The activation signal for the n process is not transmitted to the 11th+1st process.

As a result, relays CR, 5 are not energized, so relays CR, 4, and CR9 are not energized, and therefore, the equipment in the B+1 step is not activated.@Then, when the worker closes the limit switch LS2,
Since relay CR5 is energized and contact CR5a closes,
Relay CR6 is energized. As a result, contact CR6a
In order to close, even if limit switch LS2 is opened and excitation of V-CR5 is released, relay CB6 is energized. Therefore, the contact CB6b remains closed, and the 1 indicator 5 is connected to t6XK. That is, the buzzer 7 is used to notify that the workpiece has passed through the n-th process and has been carried into the (n+1)-th process.

In this way, if a process in the production line is missed, the equipment will not be started, and furthermore, when the equipment is started, a visual report will be generated or displayed by the two lamps 6 and the buzzer 7.

(Effects of the Invention) Since the present invention is configured as described above, if a workpiece conveyed to each process of the production line is missing a process, it can be immediately processed in the process immediately after the missing process. and easily discoverable.

This means that there are no longer any products that are missing in the process, which improves product reliability, and eliminates the need to repair defective products, resulting in increased productivity. It also has the economical effect of reducing product costs.

[Brief explanation of the drawing]

FIG. 1 is a sequence circuit diagram showing one embodiment of the present invention. FIG. 2 is a conceptual diagram showing the process order. 1... Sequence circuit for preventing process skipping Patent applicant: 2 people outside Toyota Motor Corporation 1:51 Figure 1: Second sieve circuit of engineering na Coole PZ]

Claims (2)

[Claims] (1) In a production line having multiple processes, a start signal generating means for generating a start signal to start the equipment is provided in each process, and the start signal from the start signal generating means for each process is transmitted to each process. The apparatus is characterized in that the equipment for the process located in the next process is started only when a start signal from the start signal generation means in the process located before the process is inputted. A method to prevent process skipping. (2) In a state where the activation signal from the activation signal generation means in the process located before the relevant process is not input,
2. The process skipping prevention method according to claim 1, wherein when the process is started, the process is not started and an alarm is generated or displayed.