A four-point clamping fixture

Abstract

The invention discloses a four-point clamping fixture, which comprises a fixture seat, a positioning plate, a positioning bushing, three sets of end face clamping devices and a set of transverse clamping devices. The positioning plate is arranged on the fixture seat by the positioning bushing; the end face of a workpiece is clamped by matching the positioning plate and the end face clamping devices; four radiation ribs are clamped in a transverse direction by the transverse clamping devices; power is provided for the clamping devices by oil cylinders; the oil cylinders are respectively arranged at the middle part and the rear part of the outer cylindrical surface of the positioning plate. According to the four-point clamping fixture disclosed by the invention, the workpiece is clamped by the three sets of end face clamping devices and a set of transverse clamping devices, i.e. clamping is located at three points on the plane of the positioning plate and one point which is vertical to the plane and is located in the transverse direction, and therefore, clamping deformation caused by redundant positioning can be effectively eliminated, high machining precision can be obtained, and the problem of the clamping deformation of thin-walled parts, such as the four radiation ribs and the like, are successfully solved.

Description

technical field [0001] The invention relates to an auxiliary device of a machine tool, in particular to a four-point clamping fixture for clamping thin-walled parts such as four radial ribs on a machine tool. Background technique [0002] Disk parts in mechanical parts often adopt a thin-walled structure with four radial ribs, such as figure 1 and figure 2 As shown, generally the small diameter of the tail is used to install mechanisms such as bearings, and the large diameter of the front is used to support mechanisms such as the outer shell. Under the premise of meeting the strength requirements, manufacturers try to reduce weight and price as much as possible, so the walls are generally made very thin; and because the shape is relatively complex, die castings are generally used to reduce the amount of processing as much as possible. Because the manufacturing precision of die castings is not too high, and due to cooling deformation and other reasons, the shape of die cas...

AI Technical Summary

Problems solved by technology

Because the manufacturing precision of die castings is not too high, and due to cooling deformation and other reasons, the shape of die castings with thin-walled structure will not be very accurate, especially the plane where the four connecting holes with large diameter at the front are used to install the outer shell , after die-casting, it will form different heights and have a certain flatness error. If four points in the same plane are used for positioning and clamping at the same time, since three of them have determined a plane, the clamping of the fourth point The force causes the plane to bend and deform. Once the processing is completed and the parts are loosened, the accuracy and flatness of the processing surface will change due to the disappearance of the clamping force, and the parts will be unqualified.

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