CN204221608U - Float positioning core axle - Google Patents

Abstract

The utility model discloses a floating positioning mandrel, which is composed of a circular sleeve, a mandrel, a base, an expansion sleeve, a snare, a washer and a nut. The round sleeve on the large-diameter end of the mandrel is locked with bolts, the small-diameter end is provided with an external thread that matches the nut, and the middle section of the mandrel is provided with a taper shaft equipped with an expansion sleeve. The expansion sleeve is composed of a ring, a washer and a nut. Form an axial spiral expansion structure. The utility model is provided with a wedging linkage structure composed of external convex teeth and grooves on the joint surface of the circular sleeve and the base. Countersunk holes are evenly distributed on the end surface of the base facing the tooth part of the workpiece bevel gear, and each countersunk hole is equipped with a post axially supported by a spring, and the protruding post is blocked by a cover plate to form an elastic telescopic structure . The utility model restricts the degree of freedom of the workpiece on the mandrel in the radial direction, axial direction and rotation around the axis. Because the positioning of the workpiece is accurate and reliable, it is beneficial to improve the precision of finishing. In addition, the inner expansion structure has no external objects, Facilitates efficient grinding of the outer shoulder of the workpiece.

Description

floating positioning mandrel

technical field

The utility model relates to a mandrel-type fixture, in particular to a floating positioning mandrel used for finishing the outer shoulder of a bevel gear.

Background technique

Bevel gears in automotive differentials and gearboxes are used to transmit torque, and such heavy-duty transmission parts must have sufficient strength to meet the use requirements. In order to improve the structural strength of the bevel gear, on the one hand, it is made of high-strength alloy steel, and on the other hand, it is produced by precision forging forming technology, and then the manufacturing quality is improved through tooth finishing and outer shoulder finishing. The bevel gear belongs to a kind of angular transmission parts, the structure is very special, and it is difficult to clamp the outer shoulder after finishing machining. In the prior art, the tooth mold fixture is paired with the workpiece bevel gear for positioning. This kind of fixture is fast in clamping and reliable in positioning, and the finishing production efficiency of the workpiece bevel gear is high under stable conditions. In reality, the finishing quality of this fixture mainly depends on the manufacturing quality of the tooth mold and the machining quality of the bevel gear teeth of the workpiece. Because the tooth surface is a curved surface, the forming process is difficult, and there is a certain amount of manufacturing error. When the two are matched, there must be a clamping error, and the bevel gear of the same workpiece is matched with different tooth positions, and there will be errors of different values, which is commonly known in the industry. "Gear change error", this uncertain error cannot be predicted, so the machining quality of the workpiece bevel gear is difficult to control.

Utility model content

The utility model mainly aims at the deficiencies of the prior art, and proposes a floating positioning mandrel with simple structure, easy clamping, and reliable positioning, which ensures that the machining reference of the workpiece bevel gear is consistent with the design reference.

The utility model realizes the technical goal through the following technical solutions.

The floating positioning mandrel is composed of a circular sleeve, a mandrel, a base, an expansion sleeve, a snare, a washer and a nut. The mandrel is a slender shaft with multi-section shoulders, the large diameter end is a cylindrical shaft, and the small diameter end is provided with an external thread that cooperates with the nut. For locking, the base is fitted on the mandrel close to the gap of the circular sleeve, and the tapered shaft section on the mandrel is equipped with an expansion sleeve. The expansion sleeve is composed of a ring, a washer and a nut to form an axial spiral expansion structure. The improvement is that: the end surface of the circular sleeve facing the base is evenly distributed with external convex teeth, and the side of the base facing the circular sleeve is provided with an equal amount of grooves at corresponding positions, and the two are wedged together to form a linkage structure. 3 to 6 axial counterbores are evenly distributed on the end surface of the base facing the tooth part of the workpiece bevel gear, and each counterbored hole is equipped with a post axially supported by a spring, and the protruding post is supported by a cover plate. The sealing file constitutes an elastic expansion and contraction structure.

As a further improvement, the convex teeth configured on the circular sleeve and the grooves configured on the base are both rectangular, and they are matched with each other with a clearance fit.

As a further improvement, the joint surface of the washer and the nut is a spherical structure.

As a further improvement, the spring is a compression spring.

As a further improvement, the outstretched end of the post is a cylindrical rod, the diameter of which is equal to the tooth spacing value on the pitch circle of the bevel gear teeth of the workpiece, and the rod end is a semicircle.

Compared with the prior art, the utility model has the following positive effects:

1. The floating positioning structure of the pile on the base is simple and easy to manufacture;

2. The degree of freedom of the radial, axial and axial rotation of the workpiece bevel gear on the mandrel is restricted, and the positioning is accurate and reliable, which is conducive to improving the precision of finishing;

3. The internal expansion and tightening structure does not affect the grinding of the outer shoulder of the workpiece bevel gear, which is beneficial to improve work efficiency.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the structure of the utility model.

Fig. 2 is a sectional view of Fig. 1 A-A.

Detailed ways

Below according to accompanying drawing and in conjunction with embodiment, the utility model is further described.

The floating positioning mandrel shown in Fig. 1 is composed of a circular sleeve 1, a mandrel 2, a base 3, an expansion sleeve 4, a snare 5, a washer 6 and a nut 7. The mandrel 2 is an elongated shaft each provided with multi-section shoulders, the large-diameter end is a cylindrical shaft, and the small-diameter end is provided with an external thread that cooperates with the nut 7 . The round sleeve 1 fitted on the large-diameter end of the mandrel 2 is radially locked by the bolt 2.1, and the base 3 is fitted next to the round sleeve 1 on the mandrel 2, and the base 3 and the mandrel 2 are in clearance fit. The middle section of mandrel 2 is provided with a section of taper shaft, and the thin-wall expansion sleeve 4 is set on the taper shaft. The outer wall of expansion sleeve 4 is a cylinder, and its outer wall is in clearance fit with workpiece bevel gear 8 inner holes when not subjected to mechanical force. The expansion of the expansion sleeve 4 set on the mandrel 2 is controlled by the axial screw expansion mechanism composed of the coaxial sleeve 5, the washer 6 and the nut 7. The nut 7 is tightened so that the expansion sleeve 4 moves to the large end of the cone shaft. Tighten the workpiece bevel gear 8, and loosen the nut 7 to restore the expansion sleeve 4 to its original state, which is convenient for the workpiece bevel gear 8 to withdraw from the mandrel 2 or reinstall it. In this embodiment, the joint surface of the washer 6 and the nut 7 is a spherical structure, which is conducive to uniform pressure. In order to make the base 3 rotate with the mandrel 2, the utility model uniformly distributes outward convex teeth on the end face of the round sleeve 1 facing the base 3, and the corresponding position of the end face of the base 3 facing the round sleeve 1 is provided with an equal amount of concave teeth. Groove, external convex teeth and grooves are wedged together to form a linkage structure. In this embodiment, two convex teeth are arranged on the end surface of the round sleeve 1, and two grooves are arranged on the end surface of the base 3. Both the convex teeth and the groove are rectangular, and the two are matched with a gap. The base 3 is a device for floating positioning of the workpiece bevel gear 8 teeth of the utility model. The device is evenly distributed with 3 axial counterbores on the end face facing the workpiece bevel gear 8 teeth. Each counterbored hole is equipped with a Spring 3 axially supported column pile 3.2. The spring 3 is a compression spring, and the outwardly protruding column pile 3.2 is blocked by a cover plate 3.3 to form an elastic telescopic structure. The end of the column pile 3.2 protrudes and inserts into the tooth portion of the workpiece bevel gear 8 to form an anti-rotation structure. In order to achieve that the post 3.2 has sufficient bending strength and can better cooperate with the 8 teeth of the workpiece bevel gear, the extended end of the post 3.2 in this implementation is a cylindrical rod, and the diameter of the cylindrical rod is equal to that of the workpiece bevel gear. The value of the tooth spacing on the degree circle of the 8-tooth part.

The utility model makes the radial, axial and axial rotation degrees of freedom of the workpiece bevel gear 8 on the mandrel 2 all restricted, and the positioning of the workpiece bevel gear 8 is accurate and reliable, which is conducive to improving the precision of finishing. The internal expansion and tightening structure has no external objects, which is convenient for grinding the outer shoulder of the workpiece bevel gear 8, and is beneficial to improving work efficiency.

Claims (5)

1. A floating positioning mandrel, which consists of a circular sleeve (1), a mandrel (2), a base (3), an expansion sleeve (4), a snare (5), a washer (6) and a nut (7) ; The mandrel (2) is a slender shaft with multi-section shoulders, the large diameter end is a cylindrical shaft, and the small diameter end is provided with an external thread that cooperates with the nut (7), and the mandrel (2) is large The round sleeve (1) set on the diameter end is radially locked by the bolt (2.1), and the base (3) is next to the round sleeve (1) on the mandrel (2) and the gap set base (3) is set on the mandrel (2). The tapered shaft section is equipped with an expansion sleeve (4), and the expansion sleeve (4) is composed of a collar (5), a washer (6) and a nut (7) to form an axial spiral expansion structure; it is characterized in that: the circular sleeve (1) The end surface facing the base (3) is evenly distributed with convex teeth, and the side of the base (3) facing the ring sleeve (1) is provided with the same amount of grooves at corresponding positions, and the two are wedged together to form a linkage structure; the base There are 3 to 6 axial counterbores evenly distributed on the end face of the seat (3) facing the tooth portion of the workpiece bevel gear (8), and a column pile (3.2) axially supported by a spring (3.1) is installed in each counterbore, The protruding column pile (3.2) is sealed by the cover plate (3.3) to form an elastic telescopic structure. 2. The floating positioning mandrel according to claim 1, characterized in that: the outer protruding teeth of the sleeve (1) and the grooves of the base (3) are both rectangular, and the two match and the gap Cooperate. 3. The floating positioning mandrel according to claim 1, characterized in that: the joint surface of the washer (6) and the nut (7) is a spherical structure. 4. The floating positioning mandrel according to claim 1, characterized in that the spring (3.1) is a compression spring. 5. The floating positioning mandrel according to claim 1, characterized in that: the extended end of the column pile (3.2) is a cylindrical rod, and the diameter of the cylindrical rod is equal to the tooth spacing on the pitch circle of the tooth part of the workpiece bevel gear (8) value, the rod end is semicircular.