CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims benefit of Chinese Patent Application No. 201810351792.5, filed on Apr. 19, 2018, the contents of which are hereby incorporated by reference in its entirety.

BACKGROUND

The machining process for a wheel usually requires three-procedure machining. The front, the rim, the center hole and other parts of the wheel are usually machined in the second procedure. However, due to the difference in outer diameter parameters of wheels of different sizes, it is difficult to machine hubs of different sizes with a set of fixture within the limited travel of a chuck. In the actual machining process, whenever wheels of different sizes need to be replaced, a set of parts or even a complete set of fixture needs to be replaced, which increases the production assistance time of the workshop, reduces the production efficiency and increases the labor intensity of workers. If an automatic fixture adapting to multiple different sizes of wheels can be researched and developed, the production efficiency will be greatly improved.

In addition, the maximum clamping force that the fixture can provide will be partially lost with the gradual increase of the rotational speed. The design of a suitable centrifugal force compensation mechanism can ensure the safety and reliability of the machining.

SUMMARY

The present disclosure relates to the field of automobile engineering, specifically to a wheel fixture.

The objective of the present disclosure is to provide a wheel fixture.

A wheel clamp includes a clamping jaw, a first positioning pull rod, a balance block housing, a first guide shaft, a deflection block, a balance block6, a base, pins, second positioning pull rods, a protection ring, airtight bases, airtight ejector rods, airtight support blocks, second guide shafts, airtight covers, pressure plates, first pins, first screws, second screws, a chuck body, a tightening screw, a third screw, a first O ring, fourth screws, slotted pan head set screws, second O rings, third O rings, a fifth screw, a main shaft, a sixth screw, a spring, first hexagon head hole screws, a second hexagon head hole screw, seventh screws, eighth screws, and ninth screws.

The base is connected to the main shaft by the fifth screw, the chuck body is fixed to the base by the third screw, the tightening screw connects the chuck body with the main shaft, and the protection ring presses the first O ring to the gap between the chuck body and the base, plays a sealing role and is tightened with the sixth screw. The lower surfaces of the six groups of second positioning pull rods are engaged with the toothed surface of the chuck body and tightened with two second screws respectively, the first positioning pull rod is connected and fixed to the second positioning pull rods by the two pins, the clamping jaw is connected and fixed to the first positioning pull rod by the two first screws and the two first pins, the balance block housing is connected and fixed to the base by the seventh screws, the first guide shaft passes through a through hole of the balance block housing and passes through the deflection block, two ends of the balance block housing restrict the axial movement of the first guide shaft via screws, the balance block is mounted in an inner groove of the balance block housing, the two second guide shafts pass through the through holes of the balance block and enter a bottom hole of the balance block housing, the second guide shafts are tightened on corresponding threaded holes of the balance block housing via the two first hexagon head hole screws, and the axial movement of the two second guide shafts is restricted. The spring is arranged in a bottom hole of the balance block, the second hexagon head hole screw is tightened on a corresponding threaded hole of the balance block housing to restrict the axial movement of the spring, the two pressure plates are mounted at the two ends of the first positioning pull rod, and the pressure plates are connected and fixed to the balance block housing by a group of eighth screws to restrict the movement of the first positioning pull rod in the axial direction of the main shaft. Three groups of airtight mechanisms are uniformly distributed in the circumferential direction of the upper surface of the base, in which the airtight base is connected and fixed to the base by a group of ninth screws, the third O ring is mounted in a lower groove of the airtight base, the airtight ejector rod is mounted in a circular hole of the airtight base, two slotted pan head set screws are used to restrict the rotation of the airtight ejector rod, the second O ring is mounted between the airtight base and the airtight ejector rod, the airtight support block is connected and fixed to the upper surface of the airtight ejector rod by a fourth screw, and the airtight cover seals the air passage inside the base through a group of ninth screws and a third O ring.

The clamping jaw is made of high-strength aluminum alloy.

The balance block housing, the first guide shaft and the deflection block are made of CrMo material for resisting high centrifugal force.

The fixture can adapt to multiple sizes of wheels by adjusting the position of the stepped clamping jaw on the first positioning pull rod, each position can adapt to two sizes, and the fixture finally can adapt to multiple sizes of wheels by moving four positions.

The two slotted pan head set screws are kept horizontal in the slotted direction during use, pressed into slots by a flexible wire and tightened to relax.

The two first hexagon head hole screws and the second hexagon head hole screw are kept identical in hole directions during use, and the flexible wire is passed through the hexagon head hole screws and tightened for relaxing.

The outer surface of the deflection block is machined by low-speed wire cutting to ensure the surface roughness.

A plurality of weight reduction pits is disposed in the lower surface of the base.

The positioning pull rods have height difference due to wear after long-term use, so the positioning pull rods are designed in two parts in the present disclosure: a first positioning pull rod and second positioning pull rods, which facilitates the adjustment of the height clearance of the fixture.

The balance block housing is connected with the base by grooves and pins besides screws to ensure accurate positioning.

The balance block is restricted by the second guide shafts to a fixed height such that sufficient clearances are reserved between the upper and lower surfaces of the balance block and the balance block housing and the base to prevent interference and affect the smooth operation of the fixture.

Compared with the existing commercial wheel fixtures, the fixture of the present disclosure has the advantages of simple structure, reliable performance and greatly reduced weight, can adapt to multiple sizes of wheels, and has larger machining flexibility.

