RU2751387C1 - Device for restoring worn sliding bushings made of non-ferrous metals - Google Patents

Abstract

FIELD: mechanical engineering.SUBSTANCE: invention relates to the field of mechanical engineering and can be used to restore both internal and external working surfaces of bushings made of non-ferrous alloys. The device contains an upper pressure electrode and a lower main conductive electrode made in the form of a multi-electrode housing with a support part on which a graphite sleeve with an asbestos gasket is placed on the bottom for installing worn bushings in an amount corresponding to the number of electrodes made with channels for coolant and with the possibility of forming a space for metal powder between the outer surface of the cooling channels and the inner surface of the worn bushings, at the same time, an asbestos insert and a graphite belt are placed in the upper part of the housing, pressed by the upper pressure electrode.EFFECT: invention makes it possible to speed up the process of restoring worn bushings due to the possibility of simultaneously restoring several bushings while simplifying the design.1 cl, 4 dwg

Description

The proposed invention relates to the field of mechanical engineering and can be used to restore both internal and external working surfaces of bushings made of non-ferrous alloys.

A container of a spot welding machine is known for placing bronze slip bushings in it during their restoration (Patent RU No. 123711). The device is a metal cylindrical body containing a cavity for coolant and upper and lower metal covers, and holes are drilled in the centers of the covers for placing copper cylindrical inserts with an electrically insulating coating in them, the lower cover is fixed with M12 bolts to the container body, in the bottom of the body of which is laid an asbestos gasket and a graphite ring, the inner side of the container body is lined with an asbestos ring, at the top of the body there is a graphite ring, an upper asbestos gasket and a top cover with a copper insert for fixing them on the bronze sliding sleeve.

The main disadvantage of the device is the bulkiness of the equipment, the excessive duration of the recovery time.

The closest technical solution chosen as a prototype is a device for restoring the inner worn-out surface of the connecting rod top bushing (Patent RU No. 62853) for restoring the inner worn-out surface of the connecting rod top bushing, containing a mandrel limiting the working volume, means for filling it with metal powder and sintering under pressure. The mandrel contains the lower and upper centering rings installed along the axis of the bushing and a calibration rod placed inside it, the gap between which is filled with a metal powder on a bronze basis, the upper and spot welding for heating the powder with a passing electric current to the sintering temperature, while the upper centering ring is installed with the possibility of axial movement to compress the powder, and the outer surface of the sleeve is surrounded by a heat-insulating screen. The upper centering ring and the calibration rod of the mandrel are made of graphite, the metal powder is selected from the group of ferrous bronzes, the heat-insulating screen contains an asbestos sheath, and the MT-16-18 machine is selected as a spot welding machine, which provides an operating current for sintering the powder in the mandrel in the range 12-14 kA and pressure in its working volume in the range of 0.5-10 MPa.

The disadvantage of the device for restoring the inner worn surface of the bushing of the upper connecting rod head is that when using it, the process of thermal diffusion saturation of the surface of the sliding bushings is also necessary, the diffusion process increases the recovery time of the bushings, and effective cooling of the device to the required temperature is required.

From the analysis of known similar technical solutions, it was revealed that a technical problem in this area is the need to expand the arsenal of tools for restoring worn slip bushings from non-ferrous alloys.

The technical result of the invention is to accelerate the process of restoring worn bushings, due to the possibility of simultaneously restoring several bushings while simplifying the design of the device.

To solve the technical problem and achieve the specified technical result, the device containing elements for placing worn bushings between the spot welding electrodes includes an upper clamping electrode and a lower main conductive electrode made in the form of a multi-electrode housing, presented in the form of one-piece cooling shafts with a support part, on which a graphite bushing with an asbestos gasket on the bottom is placed, for one-piece cooling shafts - electrodes made with channels for a coolant, and the outer surface of the cooling channels and the inner surface of worn bushings form a space for metal powder, while an asbestos insert is placed in the upper part of the housing and a graphite belt, pressed by the upper clamping electrode.

A device for restoring worn slip bushings from non-ferrous alloys is installed in a spot welding machine, where the electrodes are heated to a temperature of 760-770 ° C, at this temperature, metal powder diffuses into the metal of the bushing being restored.

The invention is illustrated by drawings.

FIG. 1 - upper clamping electrode;

FIG. 2 - the lower conductive multi-electrode body in section;

FIG. 3 - sectional cylindrical graphite bushing;

FIG. 4 shows a general view of the device in section.

The device contains an upper clamping electrode 1, which is pressed through a graphite belt 2 and an asbestos insert 3 to a graphite bushing 4, on the bottom of which an asbestos gasket is placed 5. On the asbestos gasket 5, recoverable bushings are installed 6. Space for filling metal powder 7, for restoring bushings 6 The lower main current-conducting electrode 8 is made in the form of a multi-electrode housing, presented in the form of one-piece cooling shafts with channels for coolant 9 and a support part, on which a graphite bushing 4 with an asbestos gasket 5 on the bottom is placed, for installing worn bushings 6 in an amount corresponding to the number electrodes - one-piece cooling shafts.

A device for restoring worn out slip bushings from non-ferrous alloys works as follows. The upper clamping electrode 1, through a graphite belt 2 with an asbestos insert 3, is superimposed on a graphite sleeve 4, on the bottom of which an asbestos gasket is placed 5. On the asbestos gasket 5, recoverable sleeves 6 are installed in an amount corresponding to the number of electrodes.

Metal powder 7 is poured into the space formed by the outer surface of the cooling shafts and the inner surface of worn bushings 6. Next, the device is installed in a spot welding machine and an electric current is supplied through the lower conductive electrode 8 with channels for cooling liquid 9. In this case, the electrodes are heated to a temperature of 760-770 ° C and the diffusion of the metal powder into the metal of the restored sleeve occurs. The remanufactured bushings are cooled and used for their intended purpose.

In comparison with the prototype, the proposed device will simplify and speed up the process of reconditioning several worn out bushings at the same time.

Claims (1)

A device for restoring worn slip bushings made of nonferrous alloys, containing two electrodes and made with the possibility of installation in a spot welding machine, characterized in that the electrodes are made in the form of an upper clamping and lower main conductive, which is made in the form of a multi-electrode housing, presented in the form of one-piece cooling shafts with a support part, on which a graphite sleeve with an asbestos gasket on the bottom is placed for installing worn sleeves in an amount corresponding to the number of one-piece cooling shafts made with channels for coolant and with the possibility of creating a space for metal powder between the outer surface of the cooling channels and the inner the surface of worn bushings, while in the upper part of the body there are an asbestos insert and a graphite belt, pressed by the upper clamping electrode.

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