On 07 March 2003, TMV solemnly held a stamping shop opening ceremony after one year of construction at the plant located in Phuc Yen town, Vinh Phuc Province. It can be considered a significant activity in strengthening the localization of Toyota’s vehicles in Vietnam, as well as demonstrating TMV’s commitment to the investment and long-term development in Vietnam.
The Stamping shop was the last in line to be operated in TMV’s plan after the Painting shop, Assembly shop and Inspection shop, but with its operations, Toyota became the first automobile manufacturer to have the completed production line with 5 processes: Stamping – Welding – Painting – Assembling – Inspection. According to the traditional concept of the automobile industry, the stamping technology is only effective with large-scale production. However, with advanced technology in molding and jigging together with the "new production line of global standards", Toyota has adopted the Stamping process flexibly for 4 different vehicle lines with smaller yields.
With 7 million USD of initial investment including workshops, A0 stamping machine with 1200 tons of pressure, body-parts of Corolla were manufactured first. After many years with many big investments of tens of millions dollar worth, tens of dies has helped to produce other body parts for the remaining vehicle lines.
To date, the number of dies has reached 28 sets that focused on producing under-body and shell-body details of Vios, Corolla, Innova and Fortuner. After being pressed by machines, all parts will be manually processed and then enter the jig process (cutting burr, perforating, edge and surface repair). In order to manufacture 1 product, the molds must be changed 3-4 times with 13 ~ 17 minutes for each changing while the pressing time is just 29 seconds. Therefore, unlike other shops, the pressing shop must manufacture following the Lot method.
In the stamping shop, control boards and Kanbans are used as a system to control planning, output and schedule intuitively and easily. Like other signboards, there is detailed information of the types and number of products needed to produce on Kanbans. In each work shift, on the control board, workers will look at the Kanbans to know the types and quantity of what they have to produce. Each Kanban displays one lot of the parts that need to be pressed (the quantity of parts in one lot will depend on the needs of each month and it will be considered carefully based on the production of other shops in order to avoid excess stock). When workers take one Kanban, they have to produce parts with the exact quantity and type of parts displayed on the Kanban. So, the next step will never fall into an excess or a deficiency condition because everything was pre-planned. This is one of the testaments to our efforts in applying the "Just in Time" principle of the Toyota Production System.
“Just-in-Time" means making "only what is needed, when it is needed, and with the quantity needed. In other words, this is the system in which the flows of materials, goods and products during transport, production and distribution have been planned carefully so that the next step can be implemented instantly by the end of the current step. Thereby, no items will fall into the unused or pending condition, and no labor or equipment must wait.
In 1996, TMV put into operation the Welding shop together with the Painting shop, Assembly shop and Inspection shop for producing the first Toyota Hiace in Vietnam. After, to expand production of other car series, in 1997, two new assembly lines were installed in the Welding shop including W1 line (for Hiace) and W2 line (for Corolla, Camry, Land Cruiser, Vios and Zace).
Currently, W1 line is used for welding of passenger cars: Camry, Corolla, Vios with tact time is 12 minutes/vehicle. Innova and Fortuner Currently, the W1 line is used for welding of passenger cars: Camry, Corolla, Vios with the tact time of 12 minutes/vehicle. Innova and Fortuner are soldered on the W2 line with the tact time of 14 minutes/vehicle. After completing all welding processes on W1 & W2 line, the car will be transferred to the general line called SBL with the tact time of 6.5 minutes/vehicle.
The order in the Welding shop is as followed:
Under rear process
Side member process
Main body process
Touch up process
Main bodies, side members and under rears are the localizable parts that are pressed in TMV’s plant. The other small parts are imported. They were put into the jig and soldered to be a main body using the point welding method in which workers use a welding gun that has two electrodes to create a high-intensity current to weld the parts together.
With hundreds of welding points along the main body, in order to improve the accuracy of these, we have implemented many useful kaizens such as:
Building a new system of Gun Guide: Gun Guide will be put into the jig directly to prevent workers from missing the welding points and its position.
A system controlling the flaking of solders: There are too many welding points for workers to check the accuracy of them all. Therefore, the welding points will be divided sequentially for 5 consecutive vehicles. If all is good, the five cars will be transferred to the next step. If not, all of them have to be rechecked. By implementing this system, both the manufacturing time and the accuracy of the welding points are guaranteed.
Memory balls on the welding gun: To maintain the accuracy of the welding points, the workers have to put 2 peaks of the gun at 90 degrees. If not, it may cause fire or perforation of the solders. After using the memory balls, the welding guns can’t be operated if they are not placed in the right angle position.
Jig accuracy: This system ensures the high precision of welding fixtures.
Especially, with the purpose of “Heijunka” in production (otherwise known as standardizing the production plan, in which the total number of vehicles to be produced (this number is determine once a month), engineers and Kaizen team have researched and manufactured one more main body jig called MBA2. Therefore, the parts of other models could be put into the MBA2 on standby after finishing MBA1 without waiting for MBA1 to be done to replace the jig and assemble parts of the next vehicles into this. So since May 2013, instead of using the “lot 5x5” method, the Welding shop has been converted its production method to Heijunka plan successfully.
In 1996, a Painting shop was put into operation at the TMV’s plant with its task in Topcoat layer completion, which is a step of polish and color for the body. Previously, all imported parts had been covered with 2 layers including ED and Primer.
Now, in order to make the quality standard for line-off, not to mention sealer step, there are 4 layers in painting including: ED, Primer, Topcoat (gloss and color).
In the Painting shop, the standard procedure is summarized as follows:
Surface pretreatment: After leaving the Welding shop, the surface of the body will be cleaned and phosphoresced to increase the anti-rust and adhesion of the ED step.
ED: After the surface pretreatment step, the body will be embedded in the ED paint tank (Electrophoretic Painting Process – E coat). This process is also known as electrode position to make a better painting on the surface. After being taken out of the ED paint tank, the body would be dried in an oven to a high temperature for drying the paint and created the hardness of the coating.
Sealer & PVC: This step helps seal the edges of steel, against the external impacts during driving (waterproof, anti kicked and noise).
Primer: Increases the adhesion of the Topcoat as well as the gloss and color. Currently, we have applied electrostatic painting processes to this step since 2001. It not only makes
a better surface, but also minimizes harm to the environment because of salvaging painting. After the primer layer, the body will be in the drying process with high temperatures.
Topcoat: It is the painting layer that creates the beauty for vehicles and shows a true color of the vehicle. Therefore, its requirements are included in 3 words "Gloss, durability and reality.” The color will be sprayed onto the primer layer by electrostatic painting process before the final gloss painting. After that, body will be dried in an oven to a high temperature for drying the surface.
Also in the Painting shop, other small steps can be mentioned such as: sticking the plastic sheet (anti-noise) and decals; painting plastic (shell mirrors, door handles and other plastic items…) with the process includes: cleaning surface, primer, topcoat.
Upon completion, the full body will be checked with a fine finish before moving to the Assembly shop.
29 August 1996, in our one-year anniversary of Toyota Motor Vietnam’s establishment, the first car was lined-off on the A2 line. From a negligible quantity in production (6-12 units/year), now, the capacity of our plant has achieved 36,500 units / year. Currently, there are two assembly lines including:
A1 line is for Camry, Vios and Corolla with the tact time of 16 minutes/unit
A2 line is for Innova and Fortuner with the tact time of 18 minutes/unit
Now, we are assembling an average of 100 units a day. Depending on the needs of customers, we will change it conformationally. Sorry, don’t understand the word or meaning.
There are 3 main steps in the Assembly shop:
In the Assembly shop, workers use bolts and specific tools for assembling thousands of parts together. To accomplish this, the workers will use hand appliances, put a force gun to tighten the components, then use balancing power tools to tighten last, and ensure the value of each clamping point. All these tools have always been calibrated periodically and checked by appropriate authorities.
One tool is a digital torque check that has been used for checking the value of the clamping point and ensuring its standard. All S-points (the important points on vehicles) will be checked once more by our Audit team before moving it to the Inspection shop.
Due to the small production volume at our plant, so we cannot use 100% automation, but use handiwork in many steps. Thus, we respect the immense and thorough technical skills of all our workers. However, TMV is always one of the best factories, but with regard to excellence and striving for perfection, the use of human manipulation is key. So far, the TMV factory takes pride in being one of the best quality factor
ies in Asia.
In 1996, the Inspection shop was also put into operation together with TMV’s plant. It was the final step in the production process before delivery to dealers. To ensure the quality standards, vehicles must be checked through 11 steps, including:
Checking paint surface, inside and outside, sealer lines and joints to make sure they won’t let in water…
Checking all slots on vehicles to ensure all of them are in proportion.
Checking the assembly of the engine to ensure the correct parts, pipe joints, electrical wire connector jacks ... of each model are installed
Checking the frame condition, S-point bolt
Adjusting LSPV - Load Sensing Proportional Valve (vehicles braking system)
Checking interior appearance and all functions
* Measuring and adjusting 3 driving angles of vehicles:
CAMBER: a measure of how far a tire tilts when steering the wheel.
CASTER: a measure in the longitudinal direction of wheel
TOEIN: adjusting the front of the wheel pointing in towards the central line of the vehicle.
* Gas loading and headlights adjustment; measurement of light intensity.
Inserting horn and airbag on the steering wheel.
Driving test on the conveyor with a maximum speed of 110km/h to test the functionality of the manual transmission and ABS brakes.
Checking brake pedal and hand brake
Checking electrical circuit by MI computer system
Checking oil leak after drum test (testing accuracy of the speedometer and checking all modes of driving)
Checking and Fixing all errors
Rain and spray testing from all sides
Driving on the road test, checking ABS brake and transmission, checking noise, car driving straight test.
Input data to computer and move vehicles to car-parking
In order to meet the standards on each step and ensure the highest quality products, at Toyota’s plant, all vehicles must go through the final check by the audit team before moving to the next steps with the motto “quality assurance in each step”. It means that all vehicles are not only checked in the inspection shop, but also in each shop to avoid omission errors to the next step.
Thanks to the core values in compliance with the standards of Toyota Global as well as the tireless efforts of all TMV’s members, we never stop improving ourselves to become the leading automobile assembling and manufacturing enterprise in Vietnam with over 30% of market shares. The love and trust from customers are indeed the greatest motivation for our company to continue to strive and kaizen for more, manufacturing "a better car always."