Crankshaft crankshaft machining devices - Drawings

4 design part

The purpose of this section of the diploma project is to develop a universal drive for rotating parts of the round rods class, in order to restore by the electric arc metallization method.

4.1 Structural Analysis

Device for treatment of crankpins of crankshafts contains supports with inserts for installation of shaft along main journals and stops for angular orientation of shaft located on body.

invention relates to machine building technology and can be used in repair of internal combustion engines.

The purpose of the invention is to increase accuracy of the connecting rod journal installation. Device for treatment of crankpins of crankshafts, comprising supports with inserts for installation of shaft by main journals and stops for angular orientation of shaft, is equipped with eccentric axes installed for fixation on housing, on which stops are installed.

Figure 4.1 shows the front support of the crankshaft crankshaft machine (SU 1017472 A).

The device consists of a front support 1 installed on the spindle of the front head of the grinding machine, and a rear support installed on the rear head. Front support has housing 2 with replaceable insert 3 corresponding to size of crankshaft root journal 8, prism 7 and bolt 6 for crankshaft attachment, folding spring-loaded stops 4 for angular orientation of shaft (alignment of axes of machined crankshaft and spindle of machine). Stops are installed on the housing by means of eccentric axes (5), which allow adjustment of stops. Rear support is arranged similarly, but has no stops.

Crankshaft is installed by its extreme main journals on inserts (3) of supports, rests by technological platform on counterweight against one of stops, which corresponds to coaxial position of one of connecting rod necks and spindle of machine, is fixed by means of prism (7) and bolt (6). After machining the journal, the shaft is unlocked and reinstalled for machining the next connecting rod journal by turning the shaft on the inserts until the next stop 4 is shaken and then reversed to contact of the stop and the base surface of the fleece (technological platform) and the cycle is repeated.

It is an advantage of the present invention that the adjustment is carried out individually for each stop, allowing for a more precise fitting of the connecting rod neck.

Disadvantages of the device are the low efficiency of installation of the part due to the use of indicator devices.

Centering device to crankpin grinding machine (SU 560735 A).

The centering device (SU 560735 A) shown in Figure 4.3 consists of a prism housing 4 installed and fixed in the recesses of the right and left clamping cartridges

In upper part of body of prism 4 (support element) in eccentric guide there installed is replaceable movable insert 5 in which external surface is displaced relative to internal basic surface. The latter is displaced relative to axis of rotation of clamping cartridge 1 by value of crank radius of crank shaft.

In the lower part of the body of the prism 4 there is a mechanism for moving the insert 5, consisting of a bracket 8 attached to the insert 5, inside of which there is a movable cracker 9 with a round swivel nut 10. Screw 2 is connected to round nut 10 and is locked by washer 3 against longitudinal movement in prism body 4.

On two opposite sides of the body of the prism 4, radial plates are fixed, having longitudinal cutouts for the value of radial movement of the insert 5, into which the heads of screws that keep the insert 5 from falling out of the body of the prism 4 enter.

At the end of the insert 5 there is a degree scale showing the vertical movement of the inner base surface of the insert 3 relative to its outer eccentric surface 4.

Crankshaft with base journal is laid on inner base surface of insert 5 and is fixed in clamping chuck 1 with hinged cover 7.

Advantage of this device is increased efficiency of alignment of machined journal of crankshaft.

This is achieved by the fact that the support element of the proposed device is equipped with a movable replaceable insert with cylindrical external and internal surfaces relative to it, the external surface of which is made eccentric with respect to the internal basic surface and is conjugated with the working surface of the support element, also made eccentric with respect to the machine centers. Note here that inner base surface of replaceable insert is formed by radius equal to that of machined surface whose center is aligned with machine center line. Besides, device is provided with mechanism for displacement of replaceable insert with nonius scale installed on end face of insert, zero mark of reference of divisions of which is applied on end face of support element.

The disadvantage of this device is the high cost and complexity of manufacture .

Crankshaft crankshaft processing device (SU 500033 A1). invention relates to machine building technology and can be used at automotive engine repair plants.

The device consists of a front support installed on the front head of the grinding machine and a rear support installed on the rear head of the machine.

Proposed device for machining crankpins of crankshafts is equipped with mechanism for fixing thrust clamp in axial direction, which is made in form of screws rigidly connected to pressure plate and interacting with gear wheels installed in body. Figure 4.3 shows the front support.

The machined crankshaft is laid on the supports by the main necks, clamped with prisms 5 and screws 4, which provide, in addition, torque transmission. The NLG body 2 is mounted on the spindle plate of the machine head.

Support is mounted on housing coaxially to it, in recess of which replaceable insert 3 is placed. Along the other support slot; made concentrically to recess for replaceable insert 3, thrust bracket 1 can be mixed coaxially to treated shaft. The bracket 1 serves to set the crankshaft to be processed along the angle of the cranks and is held by the arc pressure bar 6. The latter is pressed by holding mechanism located in housing 2 and consisting of screw 7 and gear wheels 9, into which screws rigidly connected to pressure plate 6 are screwed when they are turned. System balancing is provided by counterweight (10) fixed on the housing by screws (8).

The rear support is similar to the front support, but it does not have a stop bracket for mounting the crankshaft along the angle of the cranks and a mechanism for holding the stop bracket in the required position. Crankshaft is laid on inserts of front and rear supports so that crankpin journal, having median or close to it angular deviation from positions of other crankpins and design base, would be opposite to orienting device fixed on machine bed along support prism of which angular orientation of crankshaft is performed. The stop bracket 1 is mixed until the corresponding base stop of this bracket contacts the process platform of the shaft, which serves for its angular orientation.

After that, thrust bracket is fixed with pressing plate 6 by means of screw 7 rotation, machined crankshaft is clamped on body inserts with the help of prisms 5 and screws 4, support prism of orienting device is removed from crankpin of crankshaft and crankpin located on axis of device rotation is ground. Then, without changing the position of the thrust bracket 1 on the device and without removing the shaft from the machine, its next positions are turned to process the next and subsequent connecting rods.

The advantage of this device is the increased accuracy of shaft installation.

The disadvantage is the complexity and high cost of manufacture.

Device for grinding of crankpins of crankshafts (SU 1256930 A1), comprising front and rear heads, a faceplate installed on the front head, kinematically connected to it centerpiece with a mechanism for fixation of the processed shaft and a retainer for fixation of angular position of the shaft. In order to increase labor productivity, the device is equipped with a dividing disk, on the periphery of which there are grooves, on the centerfold there is a retainer fixed, the end of which is eccentric and installed with the possibility of interaction with grooves of the dividing disk.

invention is related to devices for grinding of surfaces of rotation, in particular to devices for grinding of crankshaft connecting rods, mainly in conditions of repair enterprises. The purpose of the invention is to increase labor productivity by eliminating the use of an indicator device during adjustment of the device. Figure 4.4 shows the front support of this device.

Proposed device comprises centrepiece 2 secured on grinding machine front head washer while dividing disk 3 with retainer 5 for locking on crankshaft key groove 4 and retainer 1 mounted on bracket secured on centrepiece 2 base. Crankshaft is installed between front and rear heads. Grooves on periphery of dividing disk 3 are shaped as involute engagement recesses, and conical end of retainer 1 is located eccentrically on guide rod. Eccentricity is equal to deviation of angle of crankpins camber in linear expression at distance of dividing radius Rd of involute engagement cavity. Figure 4.4 shows the eccentricity conventionally increased for clarity. For car crankshafts at Rd = 120 mm = 0.5 mm.

Before installation of crankshaft 4 on grinding machine, dividing disk 4 is installed on its hub and fixed on keyway. Crankshaft 4 is mounted on a grinding machine in three-cam cartridges of serial centreplanes. If the end of the retainer enters the groove on the periphery of the disc 3, the pair of connecting rod necks are respectively located in the grinding zone. Turning rod of retainer 1 by handle, dividing disk 3 is turned. Value of maximum rotation of disk 3 from rotation of rod of retainer 1 and crankshaft 4 rotating with it equals angular tolerance of position of connecting rod necks. Thus, there is no need to use an indicator device to control the position of the connecting rod necks in the grinding zone.

The exposed crankshaft 6 is clamped by the jaws of the machine cartridges. The grinding process is then performed. At the end of the process, the pairs of connecting rod necks located on the same axis, the jacks of the cartridges are separated, the rod of the retainer 1 is pulled off, and the crankshaft 4 together with the disk 3 is rotated by the angle of collapse of the connecting rod necks. The end of the retainer 1 is inserted into a further groove on the periphery of the dividing disc 3. After grinding of all connecting rod journals, crankshaft 4 is removed from three-valve cartridges.

The advantages of this design lie in the simplicity of manufacture, increased labor productivity due to the elimination of the use of an indicator device during adjustment of the device.

The main drawback of the design is that it is designed for a certain shaft diameter, that is, not universal.

4.2 Justification of selected prototype and directions of its improvement

The prototype of the designed drive, based on the analysis of the structures, takes the device for grinding the connecting rod necks (Figure 4.4), since this design is inexpensive, easy to manufacture, easy to use.

To increase the nomenculture and the productivity of the installation of sprayed parts, it is proposed to modernize the mechanism for fixing parts .

4.5 Maintenance and Repair Recommendations

All movable joints are lubricated with grease.

After all adjustments, the tightening of all bolted connections is checked.

During operation, oil in the gearbox is changed once a year.