CN112809415B - A horizontal double-sided combined milling machine fixture with four positioning planes for tractor gearbox - Google Patents

Abstract

The invention provides a horizontal double-sided combined milling machine fixture with four positioning planes of a tractor gearbox, wherein two fixed cylinders are fixed on two sides of a fixture body of the fixture, two movable cylinders are installed in a cylinder barrel above each fixed cylinder, a piston rod of each fixed cylinder moves to push a rear cover of each movable cylinder through a lever so that the movable cylinders move in the cylinder barrel, an expandable positioning pin is expanded to realize positioning and clamping when the cylinder barrel moves through an inclined plane at the front end of the piston rod of each movable cylinder, a plurality of supports are arranged on the bottom plane of the fixture body, and when a piston rod of a small cylinder pushes a wedge, a sliding column is ejected. The horizontal double-sided combined milling machine tool solves the problem that no fixture is needed for a horizontal double-sided combined milling machine aiming at four positioning planes of a gearbox of a tractor, the horizontal double-sided combined milling machine tool is completely positioned, multi-point clamping is realized, cutting force can assist in clamping, the clamping reliability is greatly improved, a blank hole is used as a positioning rough reference, a foundation is provided for uniform machining allowance of subsequent holes, and powerful guarantee is provided for fine machining of the holes.

Description

A horizontal double-sided combined milling machine fixture with four positioning planes for tractor gearbox

technical field

The invention relates to a horizontal double-sided combined milling machine fixture for four positioning planes of a tractor gearbox, belonging to the technical field of machine tool fixtures.

Background technique

As shown in Figure 1, a tractor gearbox body is equipped with input shafts, output shafts, other transmission shafts, bearings, gears, etc., by changing the transmission of the sliding gears and fixed gears installed on these shafts The main function of the gearbox is to support the transmission shafts, ensure the center distance and parallelism between the shafts, and ensure the correct installation of the tractor gearbox body components and other components connected to them.

The parameters of the tractor gearbox body are: material HT150, casting blank; from the perspective of structural process characteristics, the tractor gearbox body is a thin-walled shell cavity-shaped part, the structure is complex, the casting is not small, the rigidity is slightly worse, and it is subject to strong forces. The back is easy to deform and requires high machining accuracy; its outer surface has multiple connection planes that need to be processed, and the supporting holes are distributed on the front and rear end faces. In order to better facilitate processing and meet the accuracy requirements, four The positioning plane is an auxiliary datum; in addition to the support holes, there are a series of threaded holes on each connecting surface.

The main technical requirements are as follows:

Dimensional accuracy and geometric shape accuracy of the bearing hole - the tolerance level of the hole diameter is IT7 grade, and the geometric shape accuracy is controlled within the range of the dimensional tolerance zone;

Hole spacing tolerance - about IT9 level (0.120mm);

The parallelism between the centerlines of the bearing holes - within the tolerance range of the hole distance, the tolerance level is about 10-11;

Perpendicularity tolerance of the end to the bearing hole——100:0.050mm, about 7-8 grades;

Coaxiality tolerance of bearing holes at both ends——Φ0.015mm;

The flatness tolerance of the assembly base surface - 0.100mm, about 9 grades;

The position of each threaded hole - 0.200mm;

The surface roughness of the main bearing hole is required to be Ra<3.2um, and the surface roughness of the upper plane, front and rear planes is required to be Ra<6.3um.

The production type of the tractor gearbox body is large batch, the main equipment is a special combined machine tool, and the main processing procedures are as follows:

(1) Milling four positioning planes (horizontal double-sided combined milling machine);

(2) Milling front and rear planes;

(3) Milling the plane;

(4) Rough boring and drilling;

(5) fine boring (both sides at the same time);

(6) Drill holes and chamfer on three planes at the same time;

(7) Reaming and countersinking;

(8) Tap the threaded holes from three sides at the same time;

(9) Drilling and tapping on the observation window;

(10) Drilling, tapping, countersinking spherical surface.

But in the prior art, there is no clamp used for the first processing procedure of the tractor gearbox body, i.e. a horizontal double-sided combined milling machine clamp for milling four positioning surfaces.

Contents of the invention

The present invention proposes a horizontal double-sided combined milling machine with four positioning planes for the tractor gearbox in order to solve the problem that there is no fixture required for the horizontal double-sided combined milling machine for the four positioning planes of the tractor gearbox mentioned in the above-mentioned background technology fixture.

The present invention proposes a horizontal double-sided combined milling machine fixture with four positioning planes for tractor gearbox, including two fixed cylinders, two movable cylinders, two mandrels, several expandable positioning pins, five piston rods, and a small cylinder , cylinder barrel, clamp body, lever, some supports, sliding columns and wedge irons, two fixed cylinders are fixed on both sides of the clamp body, and two movable cylinders are installed in the cylinder barrel above each fixed cylinder, each The piston rods of the two fixed cylinders move through the lever to push the back cover of the movable cylinder so that the movable cylinder moves in the cylinder barrel. The front end of the piston rod of each movable cylinder is matched with the mandrel hole, and the front end of the mandrel is circumferentially installed. A number of expandable positioning pins, which are expanded to achieve positioning and clamping by the slope at the front end of the piston rod of the movable cylinder when the cylinder moves.

There are several supports on the bottom plane of the clamp body, and a small cylinder is also provided on the bottom plane of the clamp body. The front end of the small cylinder is connected with a wedge iron. When the piston rod of the small cylinder pushes the wedge iron, and then pushes out of the sliding column.

Preferably, a fork is installed between each fixed cylinder and the movable cylinder for supporting the lever.

Preferably, the horizontal double-sided combination milling machine fixture for the four positioning planes of the tractor gearbox further includes two spring hoops, the two spring hoops pass through the expandable positioning pins and are embedded in the annular groove of the mandrel for processing After the end, the movable cylinder returns to the original position of the positioning pin and leaves the workpiece.

Preferably, a tool setting block is installed on the cylinder bracket.

The beneficial effects of the horizontal double-sided combined milling machine clamp for the four positioning planes of the tractor gearbox according to the present invention are as follows:

1. The present invention solves the problem of the fixture required for the horizontal double-sided combined milling machine on the four positioning planes of the tractor gearbox. The fixture is completely positioned and multi-point clamped, and the cutting force can assist clamping, making the clamping reliable The accuracy is greatly increased, and the blank hole is used as the rough positioning reference, which provides the foundation for the uniform machining allowance of the subsequent holes, and provides a strong guarantee for the finishing quality of the holes.

2. All the clamping mechanisms of the present invention are combined with the wedge clamping mechanism, which can be self-locking, firm clamping, and strong reliability; in addition, pneumatic clamping is used to facilitate the control of the action sequence of the electrical system, and the clamping efficiency is high. It meets the high efficiency requirements of mass production.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

In the attached picture:

Fig. 1 is the structural representation of tractor gearbox of the present invention;

Fig. 2 is the side view of tractor gearbox according to the present invention;

Fig. 3 is a sectional view of the tractor gearbox according to the present invention;

Fig. 4 is a cut-away front view of a horizontal double-sided combined milling machine clamp for four positioning planes of a tractor gearbox according to the present invention;

Fig. 5 is a front view of the appearance of a horizontal double-sided combined milling machine fixture for four positioning planes of a tractor gearbox according to the present invention;

Fig. 6 is a cutaway side view of a horizontal double-sided combined milling machine clamp for four positioning planes of a tractor gearbox according to the present invention;

Fig. 7 is the sectional view of sliding column and wedge iron according to the present invention;

Fig. 8 is a perspective view of a horizontal double-sided combined milling machine clamp for four positioning planes of a tractor gearbox according to the present invention;

Fig. 9 is an axonometric view at one angle of a horizontal double-sided combined milling machine clamp for four positioning planes of a tractor gearbox according to the present invention;

Fig. 10 is an axonometric view at another angle of a horizontal double-sided combined milling machine fixture for four positioning planes of a tractor gearbox according to the present invention;

Fig. 11 is an exploded view of a horizontal double-sided combined milling machine clamp for four positioning planes of a tractor gearbox according to the present invention;

Among them, 1-tractor gearbox body, 2-expandable positioning pin B, 3-mandrel B, 4-expandable positioning pin A, 5-mandrel A, 6-piston rod A, 7-piston A, 8- Stop washer for round nut, 9-small cylinder, 10-cylinder barrel A, 11-front cover A, 13-sealing ring A, 14-clamp body, 15-front cover B, 16-piston rod B, 17- Lever, 18-fork seat, 21-flat key, 22-front cover C, 23-support, 25-hexagon head compression screw, 26-screw support, 28-sliding column, 29-wedge iron, 32-wedge iron Seat, 33-spring cover, 38-piston C, 39-piston rod C, 40-sealing ring B, 43-back cover, 46-plug, 47-spring hoop A, 48-spring hoop B, 49-knife setting piece.

Detailed ways

The specific embodiment of the present invention is described in further detail below in conjunction with accompanying drawing:

Specific implementation mode 1: Referring to Fig. 1-11, this implementation mode will be described. The horizontal double-sided combination milling machine clamp for the four positioning planes of the tractor gearbox described in this embodiment includes two fixed cylinders, two movable cylinders, two mandrels, several expandable positioning pins, five piston rods, small Cylinder 9, cylinder barrel 10, clip body 14, lever 17, some supports 23, sliding column 28 and wedge iron 29, the both sides of described clip body 14 are fixed two fixed cylinders, and the cylinder barrel above each fixed cylinder Two movable cylinders are installed in the 10, and the piston rod of each fixed cylinder moves through the rear cover of the movable cylinder through the lever 17 so that the movable cylinder moves in the cylinder barrel 10. Clearance fit, a number of expandable positioning pins are installed in the circumferential direction of the front end of the mandrel, and the expandable positioning pins are expanded by the slope at the front end of the piston rod of the movable cylinder when the cylinder 10 moves to realize positioning and clamping.

The bottom plane of the clamp body 14 is provided with several supports 23, the bottom plane of the clamp body 14 is also provided with a small cylinder 9, and the front end of the small cylinder 9 is connected with a wedge iron 29, when the piston of the small cylinder 9 The rod pushes the wedge iron 29, and then pushes out the sliding column 28.

Fork seat 18 is installed between each fixed cylinder and movable cylinder, is used for supporting lever 17.

A tool setting block 49 is installed on the cylinder bracket.

Two spring hoops pass through the expandable positioning pins (2 and 4), and are embedded in the annular grooves of the mandrels (5 and 3), and are used to restore the original position of the positioning pins (2 and 4) after the cylinder is retracted after the processing is completed ( non-bulging state) in order to leave the workpiece.

Each movable cylinder is provided with a front cover and a rear cover.

The horizontal double-sided combined milling machine fixture for the four positioning planes of the tractor gearbox according to the present invention is a fixture used in the first processing procedure of the tractor gearbox body, that is, the horizontal double-sided combined milling machine fixture for milling four positioning surfaces.

As shown in Figure 2, the workpiece is positioned based on the two blank holes, their end faces and the outer side of the box to achieve complete positioning; the specific positioning situation is that theoretically the positioning of the two blank holes on the same axis is limited to 4 degrees of freedom, and the end faces The positioning further restricts one degree of freedom of movement, and one outer side of the box restricts one degree of freedom of rotation. The consideration of the clamping scheme is that when the two blank holes are positioned, the expandable positioning pin of the centering clamping mechanism is used for clamping. The clamping of the end face positioning is assisted by the milling force during the processing. The box body The clamping of an outer positioning is considered to be clamped by the sliding column of the wedge clamping mechanism on the opposite side, and it can be self-locked.

When the workpiece is installed, it is first placed on the four supports 23 for pre-positioning, and then the pneumatic device of the electric control part is started, and the expandable positioning pin 2 of the clamp is sent into the workpiece positioning hole by the action of the cylinder barrel 10 by means of the lever 17 ( Wherein the expandable locating pin A4 on the other side is sent into the hole when its mandrel A5 end face is close to the workpiece end face), the expandable locating pin is moved by the inclined plane at the front end of the piston rod 6 of the cylinder when the cylinder barrel 10 moves. Expansion realizes positioning and clamping, and then the wedge iron 29 pushes out the sliding column 28 by means of the small cylinder below the clamping body so that the workpiece is abutted against the hexagon head compression screw 25 .

During processing, the milling cutters on both sides first adjust the position of the cutter (without adjusting each time) by the cutter block 49, and then can enter the cutter for processing.

After processing, start the pneumatic device, loosen the workpiece, take out the processed workpiece, and a processing cycle ends.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific examples of the present invention, and are not intended to limit the present invention, and may also be a reasonable combination of the features described in the above-mentioned implementations, within the spirit and principles of the present invention, Any modifications, equivalent replacements, improvements, etc. should be included in the protection scope of the present invention.

Claims (4)

1. A horizontal double-sided combined milling machine fixture with four positioning planes for tractor gearbox, it is characterized in that it includes two fixed cylinders, two movable cylinders, two mandrels, some expandable positioning pins, five piston rods , small cylinder (9), cylinder barrel (10), clamp body (14), lever (17), some supports (23), sliding column (28) and wedge iron (29), described clamp body (14) Two fixed cylinders are fixed on both sides of each fixed cylinder, and two movable cylinders are installed in the cylinder barrel (10) above each fixed cylinder, and the piston rod of each fixed cylinder moves through the rear cover of the movable cylinder through the lever (17) so that The movable cylinder moves in the cylinder barrel (10), and the front end of the piston rod of each movable cylinder fits in clearance with the mandrel hole. The front end of the mandrel is circumferentially equipped with some expandable positioning pins, and the expandable positioning pins are arranged by the movable The slope at the front end of the piston rod of the cylinder is expanded to realize positioning and clamping when the cylinder barrel (10) moves, The bottom plane of the clamp body (14) is provided with several supports (23), the bottom plane of the clamp body (14) is also provided with a small cylinder (9), and the front end of the small cylinder (9) is connected with Wedge iron (29), when the piston rod of small cylinder (9) promotes wedge iron (29), and then ejects sliding post (28); The positioning of the two blank holes on the coaxial line restricts 4 degrees of freedom, the positioning of the end face restricts 1 degree of freedom of movement, and the outer side of the box restricts 1 degree of freedom of rotation, and the positioning of the two blank holes adopts a centering clamping mechanism The expansion of the expandable positioning pin is used for clamping. The clamping of the end face positioning is assisted by the milling force during the processing. The clamping of the outer side of the box is considered to be the top of the sliding column of the wedge clamping mechanism on the opposite side. Tight and self-locking; When the workpiece is installed, it is first placed on the four supports (23) for pre-positioning, and then the pneumatic device of the electrical control part is started, and the expandable positioning pin (2) of the fixture is operated by the cylinder barrel (10) with the help of the lever (17). It is sent into the positioning hole of the workpiece, and the expandable positioning pin is expanded by the inclined surface at the front end of the piston rod of the cylinder when the cylinder barrel (10) moves to realize positioning and clamping, and then the wedge iron (29) is The action of the small cylinder pushes out the sliding column (28) so that the workpiece is abutted against the hexagonal head compression screw (25); During processing, the milling cutters on both sides first adjust the position of the cutter through the cutter block (49), and then enter the cutter for processing; After processing, start the pneumatic device, loosen the workpiece, take out the processed workpiece, and a processing cycle ends. 2. the horizontal double-sided combination milling machine fixture of four positioning planes of tractor gearbox according to claim 1, is characterized in that, fork seat (18) is installed between each fixed cylinder and movable cylinder, is used for supporting lever ( 17). 3. The horizontal double-sided combined milling machine fixture for the four positioning planes of the tractor gearbox according to claim 1, wherein the horizontal double-sided combined milling machine fixture for the four positioning planes of the tractor gearbox also includes two Two spring hoops pass through the expandable positioning pin and are embedded in the annular groove of the mandrel. After the processing is completed, the movable cylinder returns to the original position of the positioning pin and leaves the workpiece. 4. The horizontal double-sided combined milling machine fixture for the four positioning planes of the tractor gearbox according to claim 1, wherein a tool setting block (49) is installed on the cylinder bracket.

Images