CN104551072B - Bipyramid wedge self-centering fixture - Google Patents

Abstract

The invention provides a kind of bipyramid wedge self-centering fixture, can be consolidated with cylinder cover inner hole radial positioning, clamping, workpiece is easy for going up and down, and cylinder jacket is respectively to uniform force, and machining accuracy is high.It includes the mandrel being connected to through flange on lathe, it is characterised in that：The mandrel inner chamber is provided with pull bar, and the pull bar is connected in flange side with hydraulic cylinder piston；On described mandrel fixed axoid is cut with along its excircle, activity cone core is set with described pull bar, holding set is set with pull bar between the fixed axoid and activity cone core, described to keep set front end to be provided with the preceding wedge matched with fixed axoid, the holding set rear end is provided with the rear wedge matched with activity cone core；Terminal pad is set with pull bar on the outside of the activity cone core, the terminal pad is fixed on pull bar through multiple nuts.

Description

Double cone wedge self-centering fixture

technical field

The invention relates to a jig for processing automobile parts, in particular to a jig for a cylinder set.

Background technique

The traditional rough machining process in the cylinder liner industry, the main part of internal combustion engine parts, is rough boring, and then rough turning the outer circle. Rough boring positioning is based on the outer circle and plane positioning and clamping at both ends of the cylinder liner blank. The cylinder liner blank is formed by centrifugal casting, and the parallelism of the two ends and the outer circle are irregular. In this way, the machining allowance of the inner and outer circles of the cylinder liner is very large [the machining amount of the outer circle is 7 mm (diameter value), and the machining amount of the inner hole is 9-10 mm (diameter value)].

Advantages of Centrifugal Casting Through quantitative pouring, the inner hole can obtain good surface quality, the size tolerance of the inner hole can be controlled at IT14 level (about 1 mm), and the coaxiality of inner and outer circles can be controlled at IT11 level (0.22 mm). In this way, the roughing process of the cylinder liner can position the rough-turned outer circle partial end faces in the inner hole, and then position the rough-turned outer circle on the outer circle and the two end faces. There is a lack of fixtures suitable for the above-mentioned process in the prior art.

Contents of the invention

The technical problem to be solved by the present invention is to provide a double-cone wedge self-centering fixture, which can be radially positioned by the inner hole of the cylinder liner, with stable clamping, convenient up and down of the workpiece, uniform force on the cylinder liner in all directions, and high machining accuracy.

In order to solve the above-mentioned technical problems, the self-centering fixture of the double cone wedge of the present invention includes a mandrel connected to the machine tool via a flange, and is characterized in that: the inner cavity of the mandrel is provided with a pull rod, and the pull rod is mounted on the flange One side is connected with the piston of the hydraulic cylinder; the mandrel is cut with a fixed cone surface along its outer circumference, and the movable cone core is set on the pull rod, and the pull rod between the fixed cone surface and the movable cone core is set on the pull rod There is a retaining sleeve, the front end of the retaining sleeve is provided with a front wedge matching the fixed cone surface, and the rear end of the retaining sleeve is provided with a rear wedge matching the movable cone core; the pull rod outside the movable cone core is sleeved with The connection plate is fixed on the pull rod through a plurality of nuts.

After adopting the above technical scheme, the pull rod is tightened by the piston of the hydraulic cylinder, the movable cone core and the retaining sleeve are pushed through the connecting plate, the front wedge and the rear wedge move radially along the cone surface, and the workpiece is tightened from the inside to realize stable assembly Clamp, when the hydraulic cylinder piston is released, the radial pressure disappears, the workpiece can be removed, and it is convenient to go up and down; because multiple front wedges and multiple rear wedges are evenly distributed along the circumference in the inner cavity of the workpiece, the cylinder liner is subjected to pressure from all directions. Uniform force, no deformation, high machining accuracy.

After the clamping is completed, the workpiece is interlocked with the front wedge and the rear wedge and will not be loosened naturally. In order to solve this problem, the present invention further sets a plurality of pins radially in the middle of the retaining sleeve. The pin is fixedly connected with the movable cone core through the locking screw. When the hydraulic cylinder piston moves to the right, the movable cone core drives the retaining sleeve to move to the right through multiple pins, the radial pressure of the front wedge and the rear wedge disappears, and the workpiece is automatically released.

A ring groove is arranged along the outer surface of the front wedge, and a front wedge auxiliary positioning spring is arranged in the ring groove; a ring groove is arranged along the outer surface of the rear wedge, and a ring groove is arranged in the ring groove. There is a rear wedge assist detent spring. The positioning effect between the front wedge, the rear wedge and the workpiece is further enhanced.

A sealing ring is arranged on the shaft at the joint part with the retaining sleeve, which can limit the stroke of the retaining sleeve in the axial direction.

Description of drawings

Fig. 1 is the structural representation of double-cone wedge self-centering fixture of the present invention;

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

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As can be seen in Figure 1, the self-centering fixture of the double cone wedge of the present invention includes a mandrel 2 connected to the machine tool through a flange 1, and is characterized in that: the inner cavity of the mandrel 2 is provided with a pull rod 3, and the pull rod 3 is connected with the hydraulic cylinder piston 4 on the flange 1 side; the mandrel 2 is cut with a fixed cone surface 20 along its outer circumference, the pull rod 3 is covered with a movable cone core 5, and the fixed cone surface 20 and the pull rod 3 between the movable cone core 5 is covered with a retaining sleeve 6, the front end of the retaining sleeve 6 is provided with a front wedge 7 matching the fixed cone surface 20, and the rear end of the retaining sleeve 6 is provided with a movable cone The back wedge 8 matched with the core 5; the tie rod 3 outside the movable cone core 5 is covered with a connecting plate 9, and the connecting plate 9 is fixed on the tie rod 3 through a plurality of nuts 90.

As can be seen in Figure 2, in the axial direction, the front wedge 7 can slide along the retaining sleeve 6. In order to assemble the front wedge 7 to the retaining sleeve 6, various assembly methods can be adopted. As one of the realization methods, the retaining A plurality of ribs 60 are arranged on the outer circumference of the sleeve 6, and grooves are correspondingly provided in the inner cavity of the front wedge 7, and the grooves and the ribs 60 are clearance-fitted to realize relative sliding.

A plurality of pins 61 are arranged radially in the middle of the retaining sleeve 6 , and the pins 61 are fixedly connected to the movable cone core 5 via locking screws 62 .

A ring groove is arranged along the outer surface of the front wedge 7, and a front wedge auxiliary positioning spring 70 is arranged in the ring groove; a ring groove is arranged along the outer surface of the rear wedge 8, and the ring groove A rear wedge auxiliary positioning spring 80 is arranged in the groove.

A sealing ring 21 is provided on the shaft 2 at the joint portion with the holding sleeve 6 .

The clamping process of the present invention: the cylinder liner 10 is set outside the front wedge 7 and the rear wedge 8, the hydraulic cylinder piston 4 moves to the left, and the connecting plate 9, the movable cone core 5, the retaining sleeve 6 are sequentially tightened through the pull rod 3, and the front The oblique wedge 7 moves radially along the fixed conical surface 20 and the rear oblique wedge 8 along the conical surface of the movable cone core 5 to lock the inner cavity of the cylinder liner 10, and then the processing operation can be performed.

The blanking process of the present invention: the hydraulic cylinder piston 4 moves to the right, the axial pressure disappears, the movable cone core 5 moves to the right, the pin 61 drives the retaining sleeve 6 to move to the right, the radial pressure of the front wedge 7 and the rear wedge 8 disappears, and the cylinder Set of 10 can be removed.

Claims (1)

1. A double-cone wedge self-centering fixture, including a mandrel (2) connected to a machine tool via a flange (1), characterized in that: the inner cavity of the mandrel (2) is provided with a tie rod (3) , the tie rod (3) is connected to the hydraulic cylinder piston (4) on the side of the flange (1); the mandrel (2) is cut with a fixed tapered surface (20) along its outer circumference, and the tie rod (3) A movable cone core (5) is set on the top, and a retaining sleeve (6) is set on the pull rod (3) between the fixed cone surface (20) and the movable cone core (5), and the retaining sleeve (6) ) is provided with a front wedge (7) matching the fixed cone surface (20) at the front end, and a rear wedge (8) matching the movable cone core (5) is provided at the rear end of the retaining sleeve (6); the movable The tie rod (3) on the outside of the cone core (5) is covered with a connecting plate (9), and the connecting plate (9) is fixed on the tie rod (3) through a plurality of nuts (90); the retaining sleeve (6) There are multiple pins (61) radially arranged in the middle, and the pins (61) are fixedly connected with the movable cone core (5) through locking screws (62); along the outer surface of the front wedge (7) A ring groove is provided, and a front wedge auxiliary positioning spring (70) is arranged in the ring groove; a ring groove is arranged along the outer surface of the rear wedge (8), and a rear inclined wedge is arranged in the ring groove. A wedge auxiliary positioning spring (80); a sealing ring (21) is arranged on the mandrel (2) at the junction with the retaining sleeve (6).