SU1770404A1 - Device for circular saw tempering - Google Patents

Description

The invention relates to techniques for heat treatment of metals, namely to contact heaters used when tempering discs of wood-cutting saws.

Known devices for contact heating of hardened circular saw blades (blanks) to tempering temperature to relieve stresses and output the disk to a given hardness, usually 40-45 HRCg. They are used in the manufacture of saws according to GOST 98080.

Contact heaters usually have upper, lower plates and heating elements evenly placed in them. Plates are most often round in shape, since the heated object is a disk. Heaters in the stove are placed with a uniform step along coaxial circles. Uniform placement of the heating elements leads to the fact that the heating of the central

The зоны zone of the heater plates is usually several ^Λ tens of degrees higher than the peripheral zone. This leads to the formation of residual compressive stresses in the peripheral zone of the discharged discs and warping of the disc in a form called double-sided winging. According to GOST 980-80, the saw blade must be flat and have normalized tensile stresses in the peripheral zone. Since tempering in heaters with uniform distribution of heating elements leads to an inverse picture of the distribution of residual stresses, this increases the complexity of subsequent manual editing operations (to flatten) and forging (to apply tension).

The indicated disadvantage can be eliminated if the contact heater has a temperature non-uniform radius

1770404 A1 field - the temperature in the peripheral zone of the plates is higher than in the central one. A device for creating such a temperature field, adopted as a prototype. It has a bed, lower and upper heating plates, which are made in the form of coaxially arranged rings and discs with individual heaters separated by a heat-insulating gasket.

The known device is inconvenient in operation, since to ensure the desired temperature field with a change in the diameter of the disc being released, it is necessary to change the diameter of the plates. In addition, when a large number of coaxially arranged rings and tempering temperatures (about 500 ^and C) it is difficult to ensure the overall flatness of the working surface of prefabricated panels with the deviation not more than 0.03 mm, which is a requirement for planarizing the released disc. Prefabricated plates are more time-consuming to manufacture and repair, less reliable and increase the cost of contact heaters, since an automated temperature control system for each coaxially located ring is required.

The purpose of the invention is to improve the quality of processing of saws.

This goal is achieved by the fact that in the known device for dispensing saws, comprising a housing and component plates installed on top of each other with heating elements, the components of each plate are interconnected in a horizontal plane along a conical surface, the base of which is facing the center of the device, and the heating elements located along the conical surface.

The drawing shows a General view of the device.

It has a frame 1, lower 2,3 and upper 4,5 plates with heating elements and heat insulation 6. The upper plates 4 and 5 have the ability to raise and lower the lower plates 2 and 3 using the pneumatic cylinder 7.

The operation of the device proceeds as follows.

The upper plate 4,5 with the help of the pneumatic cylinder 7 is raised to its highest position. A releasable disk is laid on the lower plate 3, which is then pressed by the upper plate 5. The holding time is normalized depending on the heating temperature of the plates, the dimensions of the released disk and the set hardness. After the expiration of the set holding time, the pneumatic cylinder 7 raises the plates 4,5, remove the released disk and cool it.

The approach of the heating elements to the heated disk from the center to the periphery of the plates provides the set temperature law in the plates - when heating any disk, the temperature of its peripheral zone will be no lower than the central one. That is, the basic requirement of the method will be met, but at the lowest cost.

The proposed device provides the possibility of standardized tempering on plates of the same diameter of saws of any diameters within the diameter of the plates, which creates operational convenience. The cost of a device with solid plates compared with devices with prefabricated plates having several coaxially arranged and individually controlled rings is reduced by no less than 60%. The operating costs of the proposed device are reduced by at least 40%.

Claims (1)

Claim A device for tempering circular saws, comprising a housing and component plates installed one above the other with heating elements, characterized in that, in order to improve the quality of processing by uniformly distributing temperatures along the radius of the plate, the components of each plate are interconnected in a horizontal plane on a conical surface , the base of which is facing the center of the device, and the heating elements are located along the conical surface. Editor Compiled by Y. Stakhiev Tehred M. Morgenthal Corrector M. Andrushenko Order 3715 Circulation Subscribed VNIIIPI of the State Committee for Inventions and Discoveries at the State Committee for Science and Technology 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.