bortorasshinitel

The main components of this structure are: frame, posts, plates, hooks, rollers, pneumatic cylinder. The frame is welded from square and rectangular steel pipes, is assembled and stationary. To a frame by means of bolts of M6x25 of GOST 7805-70 rollers and GOST 7805-70 M12x50 bolts one (motionless) rack fasten, the second (mobile) rack is put in grooves, put on a rod of a pneumatic cylinder and fastens GOST 5927-70 M20 nut. Also to a frame by means of fastening of A080-02 of ISO of 6431 (paws) on bolts of M10x25 of GOST 7805-70 the pneumatic cylinder of A 01 080-0150-02-0 fastens. Plates to racks fasten on GOST 7805-70 M8x40 bolts. The frame is stationary and is fixed in the foundation by means of 4 M6 × 50 OST 92-9339-80 anchor bolts. Description of the developed design Structure and operation of the structure First of all, the developed side widener is used at motor transport enterprises, at car maintenance and repair stations, as well as in tire repair workshops. Pneumatic cylinder is used as power element for extension of car tyre sides. The bead expander is stationary, fixed in the foundation, but it is possible to remove it from the anchor bolts and transfer it to another place. Currently, most APP, STP and tire repair shops have their own compressor stations, so the use of pneumatic-powered equipment is very important. The pneumatic drive allows bus-repair workers to exert much less effort than would be the case with a mechanical drive. Technical characteristic of the design Technical characteristic of the developed lift is given in Table 3. Table 3-the Technical characteristic of the developed elevator the Name of an indicator the Type Value stationary, pneumatic air Pressure in the pneumatic system of 0.6 - 0.8 MPas Overall dimensions of DhShhV of 902х580х900 mm Height of raising of 500 mm the Loading capacity of 80 kg the Maximum size of tires 22.5 inches the Mass of the stand of 71 kg Thanks to the high-quality materials used at design of a bortorasshiritel it guarantees reliability of work. The output force 3545N makes it possible to easily spread the sides of any tyres. The advantages of this bead expander over others: - Attachment to the floor is made due to 4 anchor bolts, thanks to which the bead expander is more stable. - The pneumatic drive allows road transport companies to specialize in the maintenance and repair of not only passenger tires, but also low-capacity trucks. The purpose of this project was achieved and the result was the design of a pneumatic side-broadener. Design calculations of the boring expander 2.1 Design calculations 2.1.1 Selection of the main dimensions of the boring expander To perform work on this device, the wheel should be located at a convenient working height, approximately 700-800mm, taking into account the height of the grip by the tires, accept the height of the boring expander 900mm. The width of the bead expander will be 580mm, length 902mm. 2.1.2 Selection of pneumatic cylinder For selection of pneumatic cylinder size use the working pressure of pneumatic system and maximum force on stops. Knowing force at stops at maximum pressure of pneumatic network (F - not less than 3000N) and operating pressure of compressed air supply network (RV = 6-8bar), select cylinder diameter and rod diameter. For our case, Dz = 80mm, Dsh = 25mm and an output force of 354.5 kg at extension and 320 kg at retraction is suitable. Select pneumatic cylinder as per ISO 6431: PC A 01 080-0150-02-0. 2.1.3 Selection of pneumatic pipe The selection of pneumatic pipe diameter will be performed by maximum air pressure in pneumatic system. The maximum pressure in our pneumatic network is 8 bar. Let's choose a pneumatic tube with a small pressure margin. According to available data, the Elastollan C98 95C 9x12 polyurethane pneumatic tube with a maximum working pressure of 10 bar was chosen. 2.1.4 Selection of hook section Figure 5 - Hook The design diagram of the hook and the received epics is shown in Figure 5. We neglect our own weight of the hook. Initial data: hook length - 100mm = 0, 1m; concentrated force is applied to hook edge - 3545H. Let's determine hook section by strength condition (2.1) where Mi is bending moment acting on hook from force F; W - axial moment of resistance of hook cross section area. Mi = FL (2.2) Mi = 3545· 0.1 = 354.5 N· m Let us assume that the hook is made of steel St3kp (αt = 250 MPa). Then [a] = [t/s], (2.3) where s is the safety factor, s = 1.4. [a] = 250/1.4 = 178.57 MPa. Considering only the main load acting on the hook from the moment Mi, we get: (2.4) Woc = 354.5/178.57 = 1.98510-6 m3 By grade: Steel hot-rolled circle GOST 2590-88 we choose: Element: Circle 20 Mass 1 m.p. = 0.888 kg Resistance moment, Wx = 0.785 Rp Steel Grade (2.5) Rs = 0, 58· 230 = 133.40 Mpa. Operating conditions factor yc = 0.80. Modulus of elasticity, E = 206000 MPa. Check the hook strength by total load: (2.6) (2.7) a = (354.5/0.785 106 = 451.59 MPa (2.8) where A is the cross-sectional area of the hook. (2.9) And = 3.14 * (1210-3) 2 = τ=3545/4.52410-4=7.835Мпа σэ == 32.97 MPas Proceeding from a condition of durability we will receive 4.524 10-4 sq.m: σэ =32.97mpa ≤ [σ] = 178.57 MPas. Safety factor [a ]/αe = 6. The section of the element passes according to the conditions of strength and rigidity. 2.1.5 Tube cross-section selection We neglect the tube own weight. Initial data: tube length - 148mm = 0, 148m; concentrated force is applied to the tube - 3545H. Let us determine the section of the tube according to the strength condition (2.10) where Mi is the bending moment acting on the tube from the force F; W is axial moment of resistance of tube cross-section area. Mi = FL (2.11) Mi = 3545· 0,148 = 524.66 N· m Note that the tube is made of steel St3kp (αt = 250 MPa). Then [a] = [t/s], (2.12) where s is the safety factor, s = 1.4. [a] = 250/1.4 = 178.57 MPa. Considering only the main load acting on the hook from the moment Mi, we get: (2.13) Woc = 524.66/178.57 = 2,93810-6 m3 By grade: Steel hot-rolled circle GOST 2590-88 we choose: Element: Circle 25 Mass 1 m.p.= 3.85 kg Moment of resistance, Wx = 1.533 10-6 m3 Steel grade - St3kp Design resistance of steel, Ry = 230 MPa Design resistance of steel to shear: Rs = 0.58· Ry; (2.14) Rs = 0, 58· 230 = 133.40 Mpa. Operating conditions factor yc = 0.80. Modulus of elasticity, E = 206000 MPa. Let's check hook durability on total loading: (2.15) (2.16) σ = 524.66/1.533 10-6 =342.24 MPas (2.17) where And - hook cross-sectional area. (2.18) And = 3.14*12.52 = τ=3545/4.52410-4=7.223Мпа σэ == 28.99 MPas Proceeding from a condition of durability we will receive 4.908 10-4 sq.m: σэ =28.99mpa ≤ [σ] = 178.57 MPas. Safety factor [a ]/αe = 6. The section of the element passes according to the conditions of strength and stiffness