CN207103885U - Internal expanding type clamp - Google Patents

Abstract

The utility model relates to an internal expanding type clamp, which comprises a base, wherein a mandrel is arranged on one side of the base; a tapered sleeve having a tapered outer surface; the central hole of the conical sleeve is sleeved on the mandrel, so that the conical sleeve can slide along the mandrel; the fixed sleeve is sleeved outside the conical sleeve and is fixed relative to the base; a plurality of strip-shaped holes are arranged on the fixed sleeve; a plurality of sliding blocks which are respectively arranged in the strip-shaped holes; the first side surface of each sliding block abuts against the conical outer surface of the conical sleeve, and the second side surface, opposite to the first side surface, of each sliding block is suitable for abutting against a clamping hole of a workpiece to be clamped; and the tightening device is arranged at the end part of the conical sleeve far away from the base and is suitable for applying force to the conical sleeve to enable the conical sleeve to move towards the base, so that the sliding blocks can move outwards in the radial direction to clamp the workpiece to be clamped. According to the utility model discloses an internal expanding type anchor clamps centering is accurate, install and remove easily and simple structure, manufacturing cost are lower.

Description

An internal expansion fixture

technical field

The utility model relates to a clamp for mechanical processing, in particular to an internal expansion clamp for clamping a workpiece with an inner hole for subsequent processing.

Background technique

Usually, for motor assembly, the axial positioning of the motor is realized by designing positioning features on the corresponding end parts before the stator silicon steel sheet and the motor casing are assembled. It can also be designed that after the stator is heat-fitted to the motor housing to form a stator-housing assembly, a positioning hole can be processed on the end face of the motor housing, and the position tolerance of the positioning hole must be controlled within a small range (for example, less than 0.04 mm), which is important for controlling the size of the motor air gap and axially connecting the motor housing to the reducer and various gear assemblies within the allowable error range. The positioning hole will be more precisely positioned than the positioning feature.

At present, the positioning of the stator-housing assembly on the processing machine tool is generally realized by a clamp installed in the inner hole of the stator, so as to perform subsequent processing on the stator-housing assembly. There are currently two main types of fixtures installed in the inner hole of the stator: one is to use a rigid mandrel passing through the inner hole of the stator as a positioning fixture, and the other is to use a multi-piece clamp that includes a tapered shaft and several tapered sleeves. The tapered inner tension clamp is used to clamp the inner hole of the stator. After the stator-housing assembly is clamped on the fixture, a numerical control machine tool (CNC) is used to process the positioning holes on the end face of the motor housing.

In the process of thermally fitting the motor housing to the stator, the deformation of the inner hole of the stator is irregular, unpredictable and complex, and the size of the inner hole of the stator changes from one point to another. The clamping of the inner hole is difficult. In addition, the processing error requirements of the positioning holes on the stator-housing assembly are very strict and important, so the fixture is required to have good centering.

Above-mentioned fixture has following shortcoming:

1. The rigid mandrel cannot adapt to the changing stator inner hole size, and the stator inner holes of different specifications need to be equipped with mandrels of different diameters. In addition, the clamping accuracy of the steel core shaft is not high enough;

2. The radial force applied by the rigid mandrel between the various parts of the stator inner hole is not equal, which will further cause different degrees of deformation of the various parts of the stator inner hole;

3. The conical internal tensioning fixture is difficult and expensive to manufacture, and due to the long axial joint length, the conical internal tensioning fixture cannot meet the high precision requirements.

Utility model content

In order to overcome all or part of the above-mentioned defects, the utility model proposes an internal expansion clamp.

An internally expanding clamp according to the present invention comprises: a base, a mandrel is arranged on one side of the base; a tapered sleeve with a tapered outer surface, and the outer diameter of the tapered sleeve is along the The direction of the base gradually becomes larger; the central hole of the tapered sleeve is set on the mandrel so that the tapered sleeve can slide along the mandrel; the fixed sleeve is set outside the tapered sleeve and It is fixed relative to the base; the fixed sleeve is equipped with a plurality of strip holes; a plurality of sliders are separately placed in each of the strip holes; the first side of each slider is in contact with the cone The tapered outer surfaces of the shaped sleeves lean against each other, and the second side opposite to the first side of each of the sliders is suitable for leaning against the clamping hole of the workpiece to be clamped; the tightening device is arranged on the tapered The end of the sleeve away from the base, the tightening device is suitable for applying force to the tapered sleeve to move the tapered sleeve towards the base, so that each of the sliders can move radially Move outward to clamp the workpiece to be clamped.

In particular, the utility model can have the following favorable aspects:

Advantageously, the shape of the first side surface of each slider matches the conical outer surface of the conical sleeve; and/or, the second side surface of each slider is in a convex arc shape curved surface, and the radius of curvature of the arc-shaped curved surface is smaller than the radius of the clamping hole of the workpiece to be clamped;

Advantageously, an outwardly protruding positioning pin is installed on the outer periphery of the mandrel, and a slide groove slidingly fitted with the positioning pin is provided on the wall of the central hole of the tapered sleeve;

Advantageously, a positioning block for circumferential positioning of the workpiece to be clamped is provided on the base, and/or a supporting block suitable for supporting the workpiece to be clamped is provided on the base;

Advantageously, the positioning block has a positioning boss for matching with the hole on the end surface of the workpiece to be clamped; the support block and the workpiece to be clamped are suitable for being fixed together by fasteners; further advantageously, The positioning block and the support block are detachably installed together with the base through countersunk nuts; the fastener is a first bolt;

Advantageously, the plurality of strip-shaped holes are evenly arranged in the circumferential direction;

Advantageously, a plurality of annular grooves are further provided on the outer circumference of the fixed sleeve at positions corresponding to the plurality of strip-shaped holes, and each of the sliders is provided with a notch at a position corresponding to each of the annular grooves;

Advantageously, one end of the mandrel away from the base is provided with a threaded hole; the tightening device includes: a flange detachably mounted on the end of the tapered sleeve; a second bolt, the second The tail end of the bolt is adapted to pass through the central hole of the flange and then connected to the threaded hole of the mandrel, and the head end of the second bolt is adapted to abut against the end surface of the flange;

Advantageously, the workpiece to be clamped includes a motor casing and a motor stator assembled together.

According to the utility model, the internal expanding clamp has simple structure, low cost and can be installed on the CNC simply by using a pressure plate, and has good adaptability to different clamping hole diameters of workpieces to be clamped. In a further solution, good positional accuracy and alignment can be achieved by using line contact between the slider and the clamping hole of the workpiece to be clamped. According to the utility model, the clamping and loosening process of the internally expanding clamp is easy, and when the workpiece is replaced, the clamp can be clamped again without taking the clamp out of the machine. The internal expansion fixture according to the present invention can be easily modified to adapt to various processing situations, such as machining thin-walled cylinders or machining teeth and so on.

Description of drawings

Fig. 1 shows a perspective view of clamping a stator-housing assembly using an internal expansion clamp according to an embodiment of the present invention;

Fig. 2 shows another perspective view of clamping the stator-housing assembly using the internal expansion clamp according to the embodiment of the present invention;

Fig. 3 is a front view of clamping the stator-housing assembly (inserting a tightening nut for clamping) using an internal expansion clamp according to an embodiment of the present invention;

Fig. 4 is an exploded view of clamping a stator-housing assembly using an internal expansion clamp according to an embodiment of the present invention;

Fig. 5 is A-A sectional view of Fig. 3;

Fig. 6 is the B-B sectional view of Fig. 3;

Fig. 7 is the C-C sectional view of Fig. 3;

Fig. 8 is a front view of clamping the stator-housing assembly (inserting the elastic nut to loosen the clamping of the assembly) using the internal expansion clamp according to the utility model;

Fig. 9 is a D-D sectional view of Fig. 8 .

Detailed ways

The structure of the internal expansion clamp according to the embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to enable those skilled in the art to fully understand the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Furthermore, it should be understood that the invention is not limited to the particular embodiments described. On the contrary, any combination of the following features and elements can be considered to implement the present invention, regardless of whether they relate to different embodiments. Accordingly, the following aspects, features, embodiments and advantages are by way of illustration only and should not be considered elements or limitations of the claims unless explicitly stated in the claims.

As shown in Figures 1 and 2, the internal expansion clamp of the embodiment of the present invention will be described below in conjunction with the stator-housing assembly. As shown in the figure, during the processing of the motor, the stator 12 is shrunk into the motor housing 13 to form a stator-housing assembly, and then the internal expansion provided according to the embodiment of the present invention can be used in the subsequent processing. A clamp is used to clamp the formed stator-housing assembly. It is conceivable that, in addition to clamping the stator-housing assembly in the motor assembly process, the internal expansion clamp according to the embodiment of the utility model can also clamp other workpieces with inner holes.

Among them, FIG. 3 to FIG. 9 show in detail the structural schematic diagrams of the internal expansion clamp of the embodiment of the present utility model. Figure 3 shows the front view of the internal expansion clamp clamping the stator-housing assembly, while Figures 5-7 show in detail the cross-sectional views of the A-A section, B-B section, and C-C section in Figure 3 .

As shown in the figure, the internal expansion fixture of the present utility model includes a base 1 provided with a mandrel 101, on which a tapered sleeve 7 capable of sliding along the mandrel 101 is arranged, and the tapered sleeve 7 is longitudinally movable with respect to said mandrel 101 and hardly movable in radial direction. In a preferred embodiment, a locating pin 11 protruding from the surface of the mandrel 101 is provided on the mandrel 101 on the base 1, and the locating pin 11 cooperates with the groove on the inner surface of the tapered sleeve 7 to realize the mandrel The circumferential positioning between 101 and the tapered sleeve 7, and the circumferential positioning between the positioning pin 11 and the tapered sleeve 7 are particularly shown in the A-A sectional view in FIG. 5 . As shown in the figure, the diameter of the inner hole of the tapered sleeve 7 used to cover the mandrel 101 remains constant, while the radius of the outer circumference of the tapered sleeve gradually increases along the direction away from the base 1, thereby realizing the tapered sleeve. The tapered shape of the outer periphery of the tapered sleeve, that is, the thickness of the wall of the tapered sleeve gradually becomes thicker along the direction away from the base 1 .

The fixing sleeve 2 is sleeved on the tapered sleeve 7 and fixed relative to the base 1 by a plurality of bolts 3, and the fixing sleeve 2 is provided with a plurality of strip-shaped holes penetrating the thickness of the wall of the fixing sleeve 2 along the circumferential direction , each strip-shaped hole extends along the longitudinal extension direction of the fixed sleeve 2, and a slider 6 is arranged in the strip-shaped hole, and one side of the slider 6 is attached to the tapered surface of the tapered sleeve 7, so The other side of the slider 6 is used to fit the surface of the central hole of the stator to clamp the stator; in order to achieve the fit, the side of the slider 6 that fits the tapered sleeve 7 is arc-shaped Conical shape, the side that fits with the central hole of the stator 12 is a cylindrical shape, and the conical shape of the slider 6 is complementary to the conical shape of the conical sleeve 7. When the conical sleeve 7 moves relative to the base 1, it also It moves relative to the slider 6 in the fixed sleeve 2 fixed on the base 1, and this movement can be converted into a radially outward movement of the slider 6, so that the inner hole of the stator 12 outside the slider 6 is inner. Tighten the grip. In the illustrated embodiment, the number of strip-shaped holes in the fixing sleeve 2 is 12, so the number of provided sliders is also 12. However, it is conceivable that the number of strip-shaped holes, sliders 6 and bolts 3 used to fix the connection between the sleeve 2 and the base 1 may be different from 12.

In order to move the tapered sleeve 7 relative to the slider 6 , a tightening device is provided, preferably at the end of the tapered sleeve 7 away from the base 1 . In particular, the tightening device is constructed as follows:

The end of the tapered sleeve 7 is fixedly connected with a flange 8 through an end bolt 9, and a central hole is arranged on the flange 8, and a threaded hole is provided on the mandrel 101 near the center of the end of the fixed flange. , the tightening bolt 10 passes through the central hole of the flange 8 and is screwed into the threaded hole on the end of the mandrel 101 on the base 1, and the head of the tightening bolt 10 abuts against the periphery of the central hole of the flange 8; By further screwing in the tightening bolt 10, the head of the tightening bolt 10 exerts a force on the tapered sleeve 7 through the flange 8 fixed on the end of the tapered sleeve 7, so that the tapered sleeve 7 is relatively fixed sleeve 2 moves in a direction towards the base 1, which moves the slider 6 radially outwards to abut against the central hole of the stator 12 to clamp the stator-housing assembly. The clamp according to the utility model utilizes the linear contact between the slider 6 and the central hole of the stator, so it can adapt to irregular deformation in the central hole of the stator, has good adaptability, and is accurate in centering. Preferably, in order to loosen the clamping of the slider 6 to the stator-housing assembly, the central hole of the flange 8 is also provided with threads, and the end of the loose nut 16 abuts on the stem of the base 1 and the nut 16 is unscrewed Cooperate with the thread of the central hole so that the tapered sleeve 7 moves relative to the fixed sleeve 2 along the direction away from the base 1 during the screwing of the loosening nut 16, so that the slider 6 moves radially inward to loosen Clamping of the stator-housing assembly. In addition to using the tightening device shown in FIGS. 5 and 9 , it is also conceivable to use other tightening devices that can move the tapered sleeve 7 , such as a force-applying handle attached to the tapered sleeve 7 .

In a preferred embodiment, a small clearance fit is realized between the bar-shaped groove on the fixed sleeve 2 and the slider 6 (the small gap is guaranteed by slow wire-feeding processing), and the two ends of the fixed sleeve 2 are provided with an annular gap. Grooves are also respectively provided at the corresponding positions of the outer circle of the slider 6, and the function of the notch is: when the set of fixtures is initially assembled, after the slider 2 is installed on the fixing sleeve 2, the two sides of the formed assembly An annular groove is formed at the end, and two O-rings are respectively inserted into the annular groove to fix the slider on the fixed sleeve 2. At this time, use the tightening bolt 10 to push the slider to move to a specific position, and the cylindrical grinding machine can be used Grinding the outer circle of slider 2.

As shown in Figure 5, a supporting block 5 is provided on the base 1, and the supporting block 5 is in contact with the end surface of the stator-housing assembly to support the stator-housing assembly; in the illustrated embodiment, The hole on the edge of the support block 5 and the stator-housing assembly is fixed by a screw; further advantageously, the screw is a long bolt 14, and the hole on the edge of the support block 5 and the stator-housing assembly is connected by the long bolt 14. Long bolts 14 are inserted from the end of the stator-housing assembly away from the support block 5; said support block 5 is advantageously evenly arranged in the circumferential direction of the base 1, so as to make the force uniform.

As shown in Figure 6, a positioning block 15 for positioning the stator-housing assembly is set on the base 1; the protrusion on the positioning block 15 is inserted into the hole on the end face of the stator-housing assembly to The circumferential position of the stator-housing assembly is positioned.

As shown in FIG. 3 , the number of the supporting blocks 5 is preferably three, and the number of the positioning block 15 is one. However, it is conceivable that the number of the supporting blocks 5 may not be 3, but other numbers more than 3. The supporting block 5 and the positioning block 15 are connected with the base 1 through countersunk bolts 4 .

The process of clamping and processing the stator-housing assembly using the internal expansion clamp according to the present utility model is as follows:

S1: place base 1 on a plane;

S2: Install the positioning pin 11 on the mandrel 101 of the base 1; after aligning the positioning pin 11 with the chute on the tapered sleeve 7, set the tapered sleeve 7 on the mandrel 101 on the base 1;

S3: use the nut 3 to fix the fixing sleeve 2 and the base 1;

S4: using a plurality of countersunk nuts 4 to lock and connect the support block 5 and the positioning block 15 to the base 1 respectively;

S5: slide the slider 6 into the fixed sleeve 2;

S6: use the nut 9 to connect the flange 8 to the end of the fixing sleeve 2;

S7: The stator-housing assembly formed by shrink-fitting the stator 12 and the housing 13 is installed on the fixed sleeve 2 along the inner hole of the stator 12, ensuring that the supporting block 5 and the positioning block 15 are in contact with the end face of the stator-housing assembly Cooperate well;

S8: use long bolts 14 to connect the holes on the outer edge of the casing 13 and the holes on the support block 5;

S9: use the tightening nut 10 to push the tapered sleeve 7 to move axially towards the base 1 through the flange 8, and accordingly the slider 6 is radially outwardly contacted with the inner hole of the stator 12 and tightened; at this time, the stator-housing is completed Axial and circumferential fixation of components;

S10: Use the pressure plate to fix the structure formed in the previous steps on the CNC; at this time, the clamping work is completed, and the machining coordinate system can be determined by using the centering rod, and then the shell is machined on the shell with a suitable tool as shown in Figure 7. The hole 17 shown;

S11: Loosen the tightening nut 10 after the processing is completed, and install the loosening nut 16. During the process of screwing the loosening nut 16 into the flange 8, the flange 8 drives the tapered sleeve 7 to move away from the base 1. Axial movement, so that the slider 6 moves radially inward, and the slider 6 is out of contact with the inner hole of the stator 12; then the long bolt 14 is loosened, and the stator-housing assembly is removed.

When the next stator-housing assembly is to be processed, just repeat steps S7-S11.

Although the utility model has been disclosed above with preferred embodiments, the utility model is not limited thereto. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present utility model should be included in the protection scope of the present utility model, so the protection scope of the present utility model should be defined by the claims range prevails.

Claims (11)

1. An internal expansion fixture, characterized in that, comprising: a base, a mandrel is arranged on one side of the base; A tapered sleeve with a tapered outer surface, and the outer diameter of the tapered sleeve gradually increases along the direction away from the base; the central hole of the tapered sleeve is sleeved on the mandrel, so that the cone a sleeve capable of sliding along the mandrel; The fixed sleeve is set outside the tapered sleeve and fixed relative to the base; the fixed sleeve is equipped with a plurality of strip holes; A plurality of sliders are arranged separately in each of the bar-shaped holes; the first side of each of the sliders abuts against the tapered outer surface of the tapered sleeve, and the first side of each of the sliders is in contact with the first The second side opposite to the side is suitable for abutting against the clamping hole of the workpiece to be clamped; A tightening device is arranged on the end of the tapered sleeve away from the base, and the tightening device is suitable for applying force to the tapered sleeve to move the tapered sleeve toward the base, so that Each of the sliders can move radially outward to clamp the workpiece to be clamped. 2. The internal expansion clamp according to claim 1, characterized in that, The shape of the first side surface of each slider is matched with the tapered outer surface of the tapered sleeve; And/or, the second side surface of each of the sliders is a convex arc-shaped surface, and the radius of curvature of the arc-shaped surface is smaller than the radius of the clamping hole of the workpiece to be clamped. 3. The internally expanding clamp according to claim 1, characterized in that, an outwardly protruding positioning pin is installed on the outer periphery of the mandrel, and a hole wall of the central hole of the tapered sleeve is provided with a The chute for sliding fit of the positioning pin. 4. The internal expansion fixture according to claim 1, characterized in that, the base is provided with a positioning block for circumferential positioning of the workpiece to be clamped, and/or, the base is provided with a suitable It is used to support the supporting block of the workpiece to be clamped. 5. The internal expansion fixture according to claim 4, characterized in that, the positioning block has a positioning boss for matching with the hole on the end surface of the workpiece to be clamped; the support block and the workpiece to be clamped Suitable for fastening together with fasteners. 6 . The internally expanding clamp according to claim 4 , wherein the positioning block and the support block are detachably mounted together with the base via countersunk nuts. 7 . 7. The internal expansion clamp according to claim 5, characterized in that, the fastening member is a first bolt. 8. The internal expansion clamp according to claim 1, characterized in that, the plurality of strip-shaped holes are evenly arranged in the circumferential direction. 9. The internal expansion clamp according to claim 1, characterized in that, a plurality of annular grooves are also provided on the outer periphery of the fixed sleeve corresponding to the positions of the plurality of strip holes, and each of the sliders corresponds to Notches are provided at the positions of each of the annular grooves. 10. The internal expansion clamp according to any one of claims 1 to 8, characterized in that, One end of the mandrel away from the base is provided with a threaded hole; The tightening device includes: a flange detachably installed at the end of the tapered sleeve; a second bolt, the tail end of which is adapted to pass through the central hole of the flange and connect with the The threaded holes of the mandrel are connected together, and the head end of the second bolt is adapted to abut against the end surface of the flange. 11. The internal expansion fixture according to claim 1, wherein the workpiece to be clamped comprises a motor housing and a motor stator assembled together.