JPS6141701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous production line system for selectively producing multiple models of products.

On a production line that produces multiple models, workers often check for differences between the models. In addition, in highly automated continuous production lines, from the time when the specified amount of material for one lot has been input at the beginning of the line, the process waits until the number of parts remaining in that lot in the entire line reaches zero before starting the next model. There is also a method of automatically detecting the model in each piece of equipment. However, each of these methods relies on the operator, takes time to complete the model changeover, requires expensive automatic identification equipment, and has problems in that the internal specifications of the products are different and the external shapes are the same. Identification itself may be difficult. Furthermore, simply counting the number of pieces processed in each piece of equipment and checking the boundaries between different models will not be able to deal with abnormal situations such as products being pulled out during the process or falling from the conveyor, and parts of different models will It had the disadvantage that it had to be assembled.

An object of the present invention is to provide a continuous production line for switching production of multiple models of products, which eliminates the drawbacks of the conventional method described above and enables efficient switching of models on a line that produces multiple models, taking abnormal conditions into consideration. There is a method to provide.

That is, the present invention provides a continuous production line in which equipment such as processing equipment, assembly equipment, and inspection equipment is connected by a transport device, in which sensors for detecting passage of parts are installed at least at the entrance and exit of each equipment, and Production of the next model is started after receiving a setup completion signal for the next process equipment that is formed based on the detected signal, and parts are sequentially moved so that there are no parts in the transfer device between the equipment that corresponds to the boundary between different models. It is characterized by its composition.

The present invention will be explained below based on embodiments shown in the drawings.

FIG. 1 is a schematic diagram showing a continuous production line for selectively producing multiple models of products according to the present invention. This production line consists of processing equipment A ₁ and A ₄ , assembly equipment A ₂ and
A ₅ , inspection device A ₃ , transport device that connects them
It is composed of a combination of C ₁ , C ₂ , C ₃ , and C ₄ . Each of the processing equipment A ₁ and A ₄ , the assembly equipment A ₂ and A ₅ , and the inspection equipment A ₃ is equipped with a counting device D that counts the number of processed pieces, a control device E that controls the start/stop of the equipment, and a counting device that controls the number of pieces. A model boundary detection device equipped with a time measurement device F that measures the time until the change occurs.
B ₁ , B ₂ , B ₃ , B ₄ , and B ₅ are installed.

The details are shown in Figure 2. The counting device D in this model boundary detection device B is used to count the number of processed pieces.
It has several registers. register d ₁ is sensor
Count the number of parts arriving at transport section C detected by S ₁ , register d ₂ counts the number of parts arriving at (processing, assembly, inspection equipment) A detected by sensor S ₂ ,
The register _d3 is used to count the number of defective products discharged from the inspection device _A3 detected by the sensor _S3 , and is provided only in the inspection device _A3 .

Now model M will be produced in one lot of X units, and then model N will be produced in one lot.
We will explain the model switching method when producing Y units in one lot. The processing from a state where there are no parts on the line and all setups for model M have been completed will be described. Machine type boundary detection device B for each equipment after setup completion
Initialize the registers of registers d ₁ and
Set d ₂ to X. Then, each time a component arrives at each transport section C or equipment A, the values of the corresponding registers d ₁ and d ₂ are subtracted by 1. Furthermore, the inspection device A ₃ discharges defective products according to the inspection results. The number is counted by register _d3 . In the equipment A ₄ downstream from the inspection device A ₃ , the number of arriving parts decreases each time a defective product is discharged from the inspection device A ₃ , so the number is subtracted from each register d ₁ and d ₂ accordingly. The above process is repeated, and when the value of register _d2 of each facility A becomes 0, the production of model M ends. However, at this time, register d ₁ must also be 0, and register d ₂ must be set to the specified time (for example, twice the cycle time).
It is necessary that the time does not change even after a certain period of time (measured by time measuring device F in FIG. 2). When these three conditions are satisfied, the control device E in FIG. 2 stops the conveyance device C,
Issue setup change instructions. When the setup is completed, after initializing the register, refer to the total number of defective products produced up to that time for the relevant model in the inspection device A ₃ of the upstream equipment, and set the register.
Set the values of d ₁ and d ₂ to (Y - total number of defective products). After that, production of N models is started upon receiving a setup completion signal from the next process equipment. In other words, production is performed by forcibly separating M and N models by one transport section. Model switching is completed by sequentially performing the above method from the upstream equipment to the downstream equipment.
The process in which model switching progresses is illustrated in FIGS. 3 and 4. FIG. 6 is a diagram illustrating a state in which transport sections in which parts are not present are sequentially moved downstream. It can be seen that the human eye can easily distinguish between the M model and the N model.

Next, we will discuss the advantages of detecting the boundary between different models and switching between models using the method described above.

(a) Counting error (when register d ₂ counts too much) Suppose that register d ₂ counts by 1 due to noise or the like. Production of the M model ends when X units are processed, but in this case, the value of register _d2 becomes 0 when X-1 units are processed. However, since there is one more component in the transport section, that component will arrive at the facility within the cycle time after register 2 becomes 0. Therefore, since one of the three conditions for issuing a setup change instruction is not satisfied, it can be identified as an abnormal state.

A case where a part is inserted between the sensors S ₁ and S ₂ in FIG. 2 can also be identified as an abnormal state.

(b) When a part is removed or dropped in transport section C ₂ Contrary to case (a), the count value in register d ₂ is accurate, but the part is removed in transport section C ₂ . Suppose that one piece is removed. Assume that in equipment A ₂ , the post-processing conditions for X machines are satisfied and the setup is completed. However, production of the next model will have to wait until equipment _A3 completes its setup. Therefore, even if equipment _A3 processes X-1 units and waits for the arrival of the X-th unit, no parts arrive and the equipment is in a so-called idle state. If this idle state continues for more than a specified time, the model boundary detection device B has no choice but to determine that a component is stuck in the conveyor section _C2 . Therefore, a message is displayed to that effect, and when the worker rushes over and looks, he confirms that there are no parts in transport section _C2 , even though the display indicates that the parts are stuck, so he can identify abnormal conditions such as removal or falling. I can do it.

As described above, when changing models using the break detection method of this lot, the abnormal conditions mentioned in (a) and (b) can be identified, so the parts at the end of the first model M can be processed in the setup of the second model N. , conversely, it is possible to prevent the first part of the second model N from being processed as the first model M.

As explained above, the present invention provides the following effects.

(1) Automatic detection of boundaries between different types of equipment in each facility can be performed without the need for expensive identification equipment.

(2) It is possible to prevent parts of the next model from being processed or assembled into the current model due to disturbances such as parts being pulled out or dropped in the transport section.

(3) In order to prevent the above (2), a method is to stop the input of the final part of the model after checking the final part of the model at the equipment at the head of the line, and start production of the next model only after there are no remaining parts in the line. Compared to this, the time required to change models can be reduced by approximately the number of retained parts x cycle time.

(4) This method can be easily applied to products for which it is difficult to identify model differences.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram showing a continuous production line for switching between multiple models of products according to the present invention;
A diagram showing a conceptual diagram of this model boundary detection device shown in the figure,
FIGS. 3 and 4 are diagrams expressing the process in which model switching progresses. Explanation of symbols A, A ₁ to _{A 5} ...Equipment such as processing equipment, assembly equipment, inspection equipment, etc., B, B ₁ to _{B 5} ... Model boundary detection device, C, C ₁ to _{C 4} ... Transport device ,D
...Counting device, E...Control device, F...Time measuring device, _S1 , _S2 , _S3 ...Sensor.

Claims (1)

[Claims] 1. In a continuous production line in which processing equipment, assembly equipment, inspection equipment, etc. are connected by conveyance equipment,
The passage of parts is detected by sensors installed at least at the entrance and exit of the conveyance device of each equipment, and the number of parts passing through the exit side sensor is counted based on the signal detected from the sensor. , a setup instruction signal is generated when the number of tasks given in advance is reached and there is no change even after a specified time, and the number of parts passing through the sensor on the entrance side is equal to the number of tasks, and the setup instruction signal by the operator is In addition to the completion signal, production of the next model is started after receiving a setup completion signal for the next process equipment formed in the same way, so that there are no parts in the transfer device between equipment that corresponds to the boundary between different models. A continuous production line method for switching production of multiple model products, which is characterized by sequentially configuring products.