What are the main components of the car seat?

The car seat components mainly include the seat cushion, the backrest, the headrest, the skeleton skin, the damping mechanism adjustment mechanism, etc. The design principle is based on the fact that the shape and curve of the seat back should be compared with the back curve and the hip curve of the human body in a relaxed state. Anastomosis, can support the lumbar vertebrae, will not cause limb numbness due to poor blood circulation, long-term ride is not easy to feel fatigue; skeleton and various institutions should be able to meet the strength (safety) requirements and use requirements, through the front and rear of the seat, The limited adjustment of the angle of the backrest and the position of the headrest up and down, so that most people are in a comfortable state.

1.Backrest

 The design of the backrest mainly refers to the strength design and design. The height and shape of the backrest should be designed to make the back muscles relax, and the back shoulders can be effectively and reliably supported, so that the driver can maintain a stable sitting posture. There must be enough side support to avoid lateral sliding during high-speed cornering. When designing, the height and width of the backrest are generally 600mm and 480mm, respectively.

 Different backrest tilt angles can result in different intervertebral disc pressures and back muscle loads. When the backrest tilt angle exceeds 110o, the disc pressure is significantly reduced, so the back tilt angle of the seat should be considered in the design. In order to improve comfort. To meet the needs of the occupants at rest, the backrest inclination should be adjustable and the adjustment range should be as large as possible. General trucks are 100°~~115°. . The bus is 95°~~135°, and the car is 80°~~170°.

In addition, the lumbar support and armrests can also reduce the pressure on the disc. When designing, the lumbar support must have a certain thickness and permeability to ensure that the weight of the occupant can be evenly distributed in the ischial tuberosity area. The position of the lumbar support should be in the 3rd to 5th lumbar vertebrae, and the support thickness should be about 5 cm. The lumbar support is divided into mechanical support and air support. The mechanical support is supported by the mechanical device, and the support portion is rigid and has poor comfort. The air support is to support the human body with an air balloon, and the airbag control valve controls the air-filling and deflation of the airbag, so that the waist is well protected and effectively supported. The lumbar support airbag is generally made of high-frequency welding of 0.4-0.8mm thick polyurethane plate, which has the characteristics of simple process, low cost, good wear resistance and long service life. It has been widely promoted by the factory. In addition to controlling the intake and exhaust of the airbag, the lumbar support airbag control valve can also function as an overflow protection. When the pressure inside the airbag exceeds the rated pressure of the airbag, the airbag control valve overflows and relieves the pressure to ensure the safe use of the airbag.

 At present, a new type of air lumbar support device {Fig. 1-1) has been newly developed in China. The device can inflate and deflate the airbags such as the neck, shoulders and waist in a regular order and frequency. The sputum or swelling, to achieve the compression of the waist, shoulders, neck and other parts, to achieve the purpose of local massage. Greatly improved comfort.

 The seat armrest should be installed in a position that conforms to the height of the elbow when sitting in the human body, and is generally installed 250 mm above the level of the seat cushion. The armrests are fixed, angle-adjustable and reversible, reversible and laterally flipped and longitudinally flipped.

 2. Cushion

 The cushion design is mainly the determination of the cushion and cushion inclination. The design principle of the cushion depth is to make full use of the backrest. Make the buttocks properly supported. The human body is under a suitable cushion, and the ischial and calf feet form a stable body support. When the seat cushion is too large, the human body trunk is relatively moved forward, the waist is not well supported, causing fatigue; when the seat cushion is too small, it may be uncomfortable because the thigh is not well supported: therefore, the seat cushion should be pressed from the buttocks to the thighs. The full-length 3/4 design is generally 400 to 480 mm. The cushion angle should be balanced with safety and comfort, generally 2 ° ~ 10 °.

 Headrest

 The headrest is an auxiliary device designed to improve the ride comfort and safety of the car. The main function of the headrest is to ensure safety. Once the car has a rear-end collision, the cervical vertebra will withstand a large acceleration and is easily injured. With the support of the headrest, the space for free movement of the head can be reduced, the impact on the cervical vertebra can be reduced, and the neck injury of the occupant can be avoided or reduced. According to national standards, the car seat headrest is a mandatory vehicle certification test for automobiles. The front seat of the car should be equipped with a headrest.

 The headrest should protect the cervical vertebrae, and the correct installation position is very important. The headrest should be installed at least flush with the upper edge of the ear, and the distance between the back of the head and the headrest should not exceed 10 cm.

 At present, VOLVO first introduced a WHIPS cervical vertebra protection system (Fig. 1-2) on the s80, consisting of a safety headrest and a seat back support structure that is designed to effectively and uniformly withstand the movement of the occupant. It consists of a built-in energy absorbing mechanism at the junction of the seat back and the seat cushion for uniform support. In the event of a rear-end collision, the back of the chair moves backwards with the occupant, first doing parallel movement before tilting slightly back. Due to the installation of deformable parts on the joint between the seat back and the seat cushion. The back of the headrest chair is connected to the seat cushion to provide an effective support for the occupant's body, thereby improving the impact of the collision force on the back of the occupant.

 4. Seat skin

 The seat skin is a layer of material wrapped around the surface of the seat assembly. It is in direct contact with the occupant, which protects the seat foam while directly reflecting the designer's design intent. The seat skin must be flame retardant, and its combustion characteristics must meet the requirements of GB 8410-1994 "Combustion Characteristics of Automotive Interior Materials".

 5. Foam cushion

 At present, cushions for cushions and back cushions are basically foamed from flexible polyurethane foam, and high-rebound flexible polyurethane foam is widely used in automobiles. Considering the comfort of the seat and the distribution of body pressure when sitting in the human body, the density of the foam cushion should be designed differently, that is, “soft and hard.” There are two main production methods. One is the splicing method, which touches the front end of the cushion with the thigh. The part is made of low-hardness foam, the part that is in contact with the ischial bone is made of medium-hardness foam, and the lower part and the sides are made of high-hardness foam. This method is complicated and inefficient, and is generally rarely used. The second is the insert method ( Figure 1-3), when casting the cushion, put high-density foam inserts in the corresponding parts of the mold, and then cast low-density foam around. This method can solve the problem of body pressure distribution and lateral support, and the process Suitable for mass production.

 6. Seat frame

 The seat frame must be able to withstand a certain load. Generally speaking, the strength of the seat is actually the strength of the seat frame. It belongs to the mandatory certification test for the whole vehicle and should meet the strength requirements of GB1 5083 1 994 The provisions of the Experimental Methods.

 The shape of the backrest and cushion frame should be designed for the purpose of satisfying the physiological characteristics of the human body and providing safe and effective support to the driver. For example, in order to avoid the side back support caused by the softness of the backrest core, it will decrease or fail during sharp turns. A convex support side support plate or support rib is added on both sides of the back frame to support the foam core to ensure the effectiveness of the support. In order to ensure the driver's waist and shoulders have good support, the curvature of the back curve of the platform is designed on the backrest frame. For the high backrest, the waist, the back and the shoulder are closely attached to the backrest for better support and safety protection. The designer designs the backrest into two parts, and the angle can be adjusted separately.

 The seat frame is generally welded from steel, but it is becoming a new trend in modern car design. The thinning of the car seat is very important. The skeleton is the key to the thinning of the seat. The material of the frame is also different. The thermoplastic molded seat frame and the magnesium seat frame are being promoted.