121results about How to "Small dimensional tolerance" patented technology

The invention provides a piston rod of a damper, belonging to the field of automobile accessories and solving the problem of low density of the conventional piston rod of the damper. The piston rod of the damper comprises the following components in parts by weight: 55-70 parts of reducing iron powder, 0.5-0.7 part of electrolytic copper powder, 0.06-0.1 part of colloidal graphite, 0.25-0.35 part of lubricant and 0.25-0.35 part of manganese sulfide. The invention also provides a preparation method of the piston rod of the damper. By means of rationally selecting ingredients for preparing the piston rod of the damper and utilizing a powder metallurgy method, the cost can be reduced, the product density can be improved, the dimensional tolerance of a product can be reduced, and the hardness of the product can be improved. Further, the dimensional tolerance of the product is reduced by using shaping, and the product density is further improved through water atomization steam treatment, so that the product density of the piston rod of the damper can reach 5.32-5.5 g/cm<3>.

The invention discloses a metal and ceramic bonding agent and a preparation method of the metal and ceramic bonding agent, a CBN grinding wheel and a manufacturing method of the CBN grinding wheel. The metal and ceramic bonding agent is composed of, by mass fraction, 75%-92% of ceramic and 8%-25% of metal. The ceramic is composed of, by mass fraction, 40%-65% of SiO2, 8%-35% of B2O3, 6%-20% of Al2O3, 5%-18% of Na2O5, 0.5%-5% of CaO, 3%-10% K2O, 0.5%-2% of MgO and 2%-6% of TiO2. The metal is composed of, by mass fraction, 55%-80% of Cu, 15%-30% of Sn and 5%-20% of Ni. The metal and ceramic bonding agent can be used as a CBN grinding wheel bonding agent and overcomes the defects that in the grinding process of the ceramic CBN grinding wheel, the surface roughness of a workpiece is large, chatter marks are generated easily, and impact resistance is poor.

The invention provides a method for producing RE510L steel of a thin specification based on an ESP sheet billet continuous coasting and rolling procedure. The method includes the steps that raw materials are selected, and the raw materials comprise, in percentage by mass, 0.03-0.07% of C, 0.10-0.40% of Si, 0.90-1.40% of Mn, 0.02-0.04% of Als, 0.008-0.020% of Ti, 0.01-0.03% of Nb, less than or equal to 0.0030% of S, less than or equal to 0.015% of P, less than or equal to 0.004% of N and the balance Fe elements; the raw materials are subjected to converter smelting and LF furnace and RH furnace refining; molten steel formed through RH furnace refining generates hot rolling strip steel of different thicknesses through an ESP production line; in the ESP production line, the rough rolling outlet temperature is 920-980 DEG C, the finish rolling outlet temperature is 800-870 DEG C; the hot rolling strip steel is cooled in a front segment laminar flow cooling manner, and the hot rolling strip steel is cooled to 550-620 DEG C and then enters a recoiling machine to be coiled into coiled strip steel; and after the coiled strip steel is cooled, leveling, coiling and entering warehouse are performed by adopting the leveling quantity of 1-2.0%. By means of the method, problems that traditional hot rolling is high in cost, energy consumption is large and the like are solved.

The invention relates to a lost foam casting die and method for a braking disc and belongs to the technical field of lost foam casting and aims to solve the technical problem of short service life. According to the lost foam casting die and method for the braking disc, lost foam casting is adopted, the hardness of a friction surface of the braking disc is uniform and the service life is long. According to the technical scheme, the lost foam casting die comprises an upper die, a lower die and a semi-circular casting lost foam pattern, wherein cavities are formed in inner surfaces of the upper die and the lower die, a casting cavity is formed between the upper die and the lower die after the upper die and the lower die are buckled, the semi-circular casting lost foam pattern is arranged in the casting cavity, multiple movable blocks are arranged in the semi-circular casting lost foam pattern, and sprue gates are formed in tops of the upper die and the lower die. The lost foam casting die and method for the braking disc are widely used for casting of the braking disc.

The invention discloses a production process for C-shaped channel steel. The production process comprises the following steps of: hot-rolling the section of a blank body material into an unfolded shape of the section of the C-shaped channel steel; correcting the size through cold rolling; cold-bending the section of the material into a shape which is the same as the section of the finished C-shaped channel steel; and improving the size precision of the product by cold-drawing and straightening and thus producing the finished C-shaped channel steel. The C-shaped channel steel processed by using the method has the advantages that: the size tolerance is small, the linearity is low and the torsion degree is small; and under the matching of a bolt, the C-shaped channel steel is high in tensilestrength, tensile yield strength, fatigue resistance and the like.

A keyswitch structure includes a base plate, a keycap, a lift mechanism, and a balance link. The lift mechanism connects between the keycap and the base plate such that the keycap can move up and down relative to the base plate. The balance link is formed substantially in a U-shaped profile. The middle portion thereof is rotatably disposed on the base plate; the two ends thereof are respectively formed in an L-shaped profile and rotatably inserted into two slot structures on the keycap or the lift mechanism or both. Compared with a conventional balance link formed in an n-shaped profile connecting a keycap and a base plate, the invention provides more diverse structural connections, conducive to structural miniaturization. Furthermore, a support of the lift mechanism includes a protrusion capable of being blocked by a limitation structure disposed on the base plate for controlling the rotation angle of the support.

The invention discloses a manufacturing method for a flexible flat cable. The manufacturing method comprises the following steps: providing a flexible base plate, and forming a metallic conductor layer on the flexible base plate; patterning the metallic conductor layer, and forming a plurality of metallic conductors which are uniformly arranged in parallel; and pressing an insulating layer onto the plural metallic conductors of the flexible base plate. After the manufacture of the plural metallic conductors in the flexible flat cable adopts the metallic patterning process, the flexible flat cable has the advantages that the space between conducting wires can be accurately controlled, and the dimensional tolerance of the size of the conducting wires can be reduced.

The invention provides a spin-forming mould for a kettle body of a sliver kettle. The spin-forming mould comprises a mould rack, a kettle body internal supporting module arranged on the mould rack, a kettle body external forming module and a kettle body closing-in and rolling module, wherein the kettle body is arranged between the kettle body internal supporting module and the kettle body external forming module; and in a rotary process of the kettle body, the kettle body closing-in and rolling module can apply pressure to the kettle body, so that the kettle body completes closing-in. According to the spin-forming mould for the kettle body of the sliver kettle, the material consumption is reduced, the labor amount of an operator is reduced and the manufacturing cost can be effectively saved, and a manufactured product is light, uniform in thickness and high in yield.

The invention relates to a method for machining a high-precision hexagonal shaft through an ordinary numerical control boring machine. A worktable is arranged in the machining range of the ordinary numerical control boring machine; two V-shaped bases are fixed on the worktable; round parts on two ends of a workpiece are separately arranged on the two V-shaped bases, and the levelness and perpendicularity of the workpiece are detected; a hexagonal aligning template is fixed on the end surface of one end of the workpiece; the hexagonal aligning template is a regular hexagon plate; the symmetry center of the hexagonal aligning template is located on the axis of the workpiece; whether the corresponding edge lines of the hexagonal aligning template rotate to be perpendicular or not is detected; the workpiece is tightly pressed after the corresponding edge lines of the hexagonal aligning template rotate to be perpendicular; corresponding surfaces of the workpiece are machined by the ordinary numerical control boring machine through a milling cutter; and firstly a pair of parallel surfaces are machined, and then the other surfaces are sequentially machined. By adopting the method, the rotation angle of the workpiece can be precisely controlled; the machining is precise; the operation is simple; and the cost is low.

A heat exchanger includes a heat exchanger housing with an exhaust gas inlet adapter and an exhaust gas outlet adapter, which encloses and bounds off a flow space for a coolant. The heat exchanger is furthermore configured with platelike heat exchanger elements arranged in parallel with each other and forming exhaust gas flow ducts, through which exhaust gas flows and around which liquid coolant flows. A heat exchanger element comprises two wall elements, which are joined together on opposite side surfaces and are configured with ribs on both surfaces. The ribs are arranged on an inner side and within the exhaust gas flow duct and on an outer side of the heat exchanger element. Adjacent heat exchanger elements arranged with outer sides facing each other are joined together at end faces abutting each other, forming a coolant flow duct having the ribs disposed therein.

A one-way clutch includes multiple rollers, a first collar and a second collar that are coupled together to form relative rotation between them, and a circular holding frame. The first collar has multiple cavities each having an inclined bottom surface. The circular holding frame has multiple slots corresponding to the rollers and exposing the cavities. The second collar is rotated to drive the circular holding frame rotating through friction force so that each roller is pushed to contact a higher portion of the inclined bottom surface and also the second collar drives the first collar rotating via pushing of the rollers. When rotational speed of the first collar is greater than that of the second collar, each roller enters a lower portion of the inclined bottom surface and separates from the second collar without transmitting torsional force between the second collar and first collar.

A method of patterning a multiple-layered resist film and a method of manufacturing a semiconductor device, which can provide an improved reliability of the semiconductor devices and a reduced operation time for an etch process, are provided. A method of patterning a multiple-layered resist film according to the present invention include: forming a lower layer resist film 104 on a semiconductor substrate; forming a silicon-containing upper layer resist film on the lower layer resist film 104; patterning the silicon-containing upper layer resist film into a predetermined geometry; and performing dry etching process for removing the lower layer resist film 104 through a mask of the patterned silicon-containing upper layer resist film 106 employing an etching gas containing oxygen (O₂) gas and argon (Ar) gas at a pressure within a range of from 0.075 mTorr to 50 mTorr both inclusive.

The invention discloses an optical signal transmitting device in the field of laser diodes. The optical signal transmitting device comprises a driving chip assembly, a laser TEC assembly and a housing, wherein the driving chip assembly and the laser TEC assembly are packaged in the housing; and a laser heat sink substrate in the laser TEC assembly comprises a first part used for installing a laserdiode chip and a second part used for installing a prism, wherein the first part is provided with a plating layer used for installing a semiconductor laser LD, and the laser heat sink substrate is further provided with a positioning structure used for positioning the prism. The device has the following beneficial effects: long wiring between the driving chip and the semiconductor laser is avoided, and the parasitic inductance and parasitic capacitance caused by long wiring are reduced, so that the problem that the parasitic inductance, parasitic capacitance, impedance mismatching and the likeinfluence the quality of high-frequency signals is solved, the use bandwidth of the optical signal transmitting device is improved, and the optical signal transmitting device is more suitable for high-speed light communication equipment.

The invention relates to a microwave dielectric ceramic material, a microwave dielectric ceramic antenna and a preparation method of the microwave dielectric ceramic antenna. The chemical compositionof the microwave dielectric ceramic material is xTiO2-(1-x)Zn2SiO4, wherein x is greater than or equal to 1.0 wt% and less than or equal to 20.0 wt%.