CN213916168U

CN213916168U - Modularization lathe tool

Info

Publication number: CN213916168U
Application number: CN202022542876.2U
Authority: CN
Inventors: 文立东; 张永强; 张文
Original assignee: CHENGDU TOOL RESEARCH INSTITUTE CO LTD
Current assignee: CHENGDU TOOL RESEARCH INSTITUTE CO LTD
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2021-08-10
Anticipated expiration: 2030-11-05

Abstract

The utility model relates to the field of modular tools, and discloses a modular turning tool, which comprises a cutting head and a bracket which are matched, wherein a boss is arranged at one end of the cutting head close to the bracket, and a recess is arranged at one end of the bracket close to the cutting head; the inner surface of the concave seat is matched with the shape of the outer surface of the boss; the boss is provided with a boss axis, and a plurality of boss spiral pressure surfaces are symmetrically arranged on the outer surface of the boss along the boss axis; the pocket has a pocket axis, and a plurality of pocket spiral pressure surfaces are symmetrically arranged on the inner surface of the pocket along the pocket axis; the pocket axis and the boss axis are coaxial to form a common axis when the pocket is connected with the boss; all boss screw pressuresThe faces and all pocket helical pressure faces satisfy the following condition: r_pSin θ ═ c (c is a constant and c > 0) -formula one. The utility model discloses the poor problem of current modularization lathe tool commonality has effectively been solved.

Description

Modularization lathe tool

Technical Field

The utility model relates to a modularization instrument field, concretely relates to modularization lathe tool.

Background

The modular tool is characterized in that components of a common tool are modularized, so that different tools can be conveniently installed and matched differently to form a new combined tool. Wherein, modularization lathe tool refers to and can install lathe tool cutter on structures such as lathe. In order to facilitate installation and replacement, the connecting part of the turning tool is made into a modular structure.

In the existing modularized turning tool, a contact surface which is used for bearing pressure and keeping the relative position of each component unchanged through the interaction of forces among various structures is arranged at the end part of each component, and in a rotatable modularized tool, the contact surface is not only used for ensuring the relative position of each component, but also used for ensuring the accuracy of rotation.

In the current common modular tool, the contact surface of each component is simply arranged according to a regular shape, such as a circular arc surface, a regular step surface and the like. However, the contact surface of each group of modularized turning tools is specially arranged, any one component in the group of modularized turning tools cannot be replaced, the modularized turning tools of different groups cannot be shared and replaced, and the purpose of universality of the modularized turning tools is not actually achieved.

SUMMERY OF THE UTILITY MODEL

The utility model provides a modularization lathe tool to solve the poor problem of current modularization lathe tool commonality.

In order to solve the above problems, the following scheme is provided:

a modular turning tool comprises a cutting head and a bracket which are matched, wherein a boss is arranged at one end of the cutting head close to the bracket, and a recess is arranged at one end of the bracket close to the cutting head; the inner surface of the concave seat is matched with the shape of the outer surface of the boss; the boss is provided with a boss axis, a plurality of boss end parts are symmetrically arranged on the outer surface of the boss along the boss axis, and a tangent plane is connected between every two adjacent boss end parts; the concave seat is provided with a concave seat axis, a plurality of concave seat ends are symmetrically arranged on the inner surface of the concave seat along the concave seat axis, and a transition curved surface is connected between every two adjacent concave seat ends; the inner surface of the socket end matches the outer surface of the boss end; the pocket axis and the boss axis are coaxial to form a common axis when the pocket is connected with the boss; each boss end part comprises a boss spiral surface and a boss mirror image spiral surface which are arranged in mirror symmetry relative to a plane passing through the boss axis; each pocket end comprises a pocket helicoid and a pocket mirror helicoid arranged mirror-symmetrically with respect to a plane passing through the pocket axis.

The scheme has the advantages that:

by having a cutting head with a convex curved surface and a carrier with a concave curved surface, a quick coupling of the cutting head and the carrier can be facilitated. The tangent plane between the adjacent boss curved surfaces and the transition curved surface between the adjacent concave seat curved surfaces provide a space for the boss to enter the concave seat and the boss curved surface to be matched with the concave seat curved surface. Through the structure, the modular processing of the lathe tool connecting part can be facilitated, the lathe tool can be used as one modular tool, the lathe tool can be more conveniently installed and replaced on various machine tools, and the universality is improved.

Further, a boss arc surface is connected between the boss helicoid and the boss mirror image helicoid; and a concave seat arc surface is connected between the concave seat spiral surface and the concave seat mirror image spiral surface.

The outer surfaces of the whole bosses are connected into a whole through the boss arc surfaces, and the inner surfaces of the concave seats form a whole through the concave seat arc surfaces.

Further, all helicoids and mirror helicoids satisfy the following helicoid pressure face formula: r_pSin θ ═ c (c is a constant and c > 0) -formula one;

on any cross section perpendicular to the central axis, the intersection line of the spiral pressure surface and the cross section is a cross section spiral line; the intersection point of the central axis on the cross section is the origin O of the cross section, and RP is the distance from any point P on the spiral line to the origin O; the position on the spiral line farthest from the original point is a big end A of the spiral line, and the distance from the big end of the spiral line to the original point is a big end radius R_A(ii) a The position on the spiral line, which is the shortest from the original point, is a spiral line small end B, and the distance from the spiral line small end to the original point is a small end radius R_B(ii) a The angle of the position angle [ AOP ] is beta, a tangent PM of the spiral line is made at a passing point P along the direction from the small end to the large end of the spiral line, a perpendicular PN of the OP is made at the passing point P along the direction from the small end to the large end of the spiral line, and the angle [ MPN ] is a helix lifting angle theta;

the straight line of the spiral pressure surface on any section vertical to the spiral line is a pressure spiral surface method section straight line; an included angle between a straight line of the cross section of the pressure spiral surface method and the central axis is set as an inclined angle alpha, when the diameter of one side of the concave seat direction is smaller, the alpha is positive, and the absolute value range of the inclined angle alpha is [8 degrees ], 30 degrees ]; the inclination angles alpha of the matched boss helicoid and the matched recess helicoid are equal.

The scheme has the advantages that:

by arranging the spiral pressure surface with uniform rules, any cutting head and any bracket with the same end part can be connected with each other, and the universality of the modularized turning tool using the modularized turning tool is effectively improved. More importantly, the modularized turning tool arranged in this way not only enables machining to be simpler, but also enables stress to be more uniform, can effectively prolong the service life of the tool, and improves rotation accuracy.

The scheme optimizes the stress state of the pressure surface in the assembling process and the working process through the boss spiral pressure surface and the concave seat spiral pressure surface which are respectively arranged on the boss and the concave seat, and improves the stability of the pressure spiral surface in the assembling process, the comprehensive capacity in the working process and the service life under the frequent loading and unloading condition. Can meet the requirements of positioning and stress under different application requirements.

According to the rule of the formula I, when the whole spiral pressure surface rotates around the axis of the spiral pressure surface, the movement speed of any point on the spiral pressure surface along the normal direction of the spiral pressure surface at the position of the point is the same. By the characteristic, synchronous contact and synchronous compression of all points during assembly can be ensured; the pressure of each point is also ensured to be the same when resisting the torque; and when the same machining error of the normal direction exists, the shape of the whole spiral pressure surface is not changed. Thereby yielding the various advantages described subsequently.

Further, the absolute value of the inclination angle α is 9 °, and the coverage of the position angle β is 39 °.

The best connection structure is achieved when the inclination angle alpha of the boss is 9 degrees and the position angle beta is 39 degrees.

Further, the diameter of the large end of the spiral line of the boss cross section is 84% of the diameter of the inscribed circle of the cutting head, and the diameter of the small end of the spiral line of the boss cross section is 74% of the diameter of the inscribed circle of the cutting head.

The specific shape of the helicoid on the boss is determined.

Further, the transition curved surface is a small arc surface.

The laminating of the spiral pressure face is conveniently carried out through the small arc face, and a rotating clearance is formed.

Further, the circumferential surface of the pocket has the same inclination angle in the axial direction as the circumferential surface of the boss.

In practice, for better fitting, different manufacturing tolerances are often applied on the basis of the nominal values, which does not affect the fact that the nominal values of the cone angles in the solution are the same. The connection between the boss and the concave seat is convenient.

Further, when the cutting head is vertically coupled to the bracket, a gap is provided between the bottom surface of the boss and the bottom surface of the recess.

After the cutting head is assembled with the bracket, the top end of the boss is not in contact with the bottom of the recess. The mutual movement is facilitated, and the assembly is completed quickly.

Further, the groove bottom of the recess has a circumferential surface with an inclination angle of 0 °.

The groove bottom of the concave seat can be provided with a peripheral surface with an inclination angle of 0 degree, so that the convex seat and the convex plate can conveniently enter the concave seat.

Furthermore, a concave surface which is inwards concave is connected between the boss spiral surface and the boss mirror image spiral surface; and an arc transition surface is connected between the concave seat spiral surface and the concave seat mirror image spiral surface.

What connect between boss helicoid and the boss mirror image helicoid is that the sunk surface can not influence the interconnect of helicoid yet, and similarly, there is curved surface or plane connection between recess helicoid and the recess mirror image helicoid as long as can not contact with the sunk surface on corresponding the boss, does not influence the boss helicoid and remove recess helicoid department can.

The thinnest wall thickness of the front end of the bracket is 30% of the radius of the inscribed circle of the cutting head, the thinnest wall thickness of the upper end of the bracket is 45% of the radius of the inscribed circle of the cutting head, and the thinnest wall thickness of the lower end of the bracket is 75% of the radius of the inscribed circle of the cutting head.

In order to facilitate the finding of the height of the cutting tip during use, the cutting tip of the cutting portion of the cutting head is located on the extension of the edge of the cutting portion of the tool holder when the cutting head and the carrier are assembled.

The bracket is provided with a knife handle, and the knife handle is arranged on one side of the concave seat. Is convenient to be connected with the machine tool.

Drawings

Fig. 1 is an explosion diagram of a modular lathe tool in the first embodiment of the present invention.

Fig. 2 is a schematic structural view of fig. 1 after being rotated by 90 degrees.

Fig. 3 is the utility model provides an assembly drawing of well modularization lathe tool.

Fig. 4 is the utility model provides a in the first embodiment a three-dimensional structure sketch map of cutting head in modularization lathe tool.

Fig. 5 is a front view of fig. 4.

Fig. 6 is a left side view of fig. 4.

Fig. 7 is a sectional view a-a of fig. 6.

Fig. 8 is a cross-sectional view E-E of fig. 6.

Fig. 9 is a schematic structural diagram of a bracket according to a first embodiment.

Fig. 10 is a front view of fig. 9.

Fig. 11 is a bottom view of fig. 9.

Fig. 12 is a sectional view taken along line B-B of fig. 11.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: cutting head 1, bracket 2, fastening screw 3, common axis 4, boss 5, cutting portion 6, first boss helicoid 100, first boss mirror image helicoid 101, second boss helicoid 110, second boss mirror image helicoid 111, third boss helicoid 120, third boss mirror image helicoid 121, first pocket helicoid 260, first pocket mirror image helicoid 261, second pocket helicoid 270, second pocket mirror image helicoid 271, third pocket helicoid 280, third pocket mirror image helicoid 281, first boss arc 7, second boss arc 8, third boss arc 9, first pocket arc 23, second pocket arc 24, third pocket arc 25, first boss plane 13, second boss plane 14, third boss plane 15, first pocket transition 29, second boss transition 30, third pocket transition 31, boss bottom 16, A pocket bottom 32, a pocket peripheral surface 35, a pocket 20, and a shank 21.

Example one

As shown in fig. 1, 2 and 3, the modular turning tool in this embodiment comprises a cutting head 1 and a bracket 2 and a fastening screw 3 for fastening the coupling of the cutting head and the bracket.

As shown in fig. 4 and 5, the cutting head has a cutting portion 6 and a boss 5, and as shown in fig. 9, 10 and 11, the carrier has a recess 20 corresponding to the boss and a shank 21 for attachment to a machine tool.

As shown in fig. 2, the central axis of the boss is a boss axis and the central axis of the pocket is a pocket axis, the respective central axes of the boss and the pocket, viewed when the cutting head is coupled with the carrier, coinciding to form a common axis 4.

As shown in fig. 4 and 5, the circumferential surface of the boss has three boss curved surfaces symmetrically arranged along the boss axis, the boss curved surfaces include a first boss curved surface, a second boss curved surface and a third boss curved surface, and the first boss curved surface includes a first boss arc surface 7, and a first boss helicoid 100 and a first boss mirror helicoid 101 which are arranged along the first boss arc surface 7 in a mirror symmetry manner; the second boss curved surface comprises a second boss arc surface 8, and a second boss helical surface 110 and a second boss mirror-image helical surface 111 which are arranged along the second boss arc surface 8 in a mirror-image symmetry manner; the third boss curved surface comprises a third boss arc surface 9, and a third boss helicoid 120 and a third boss mirror helicoid 121 which are arranged along the third boss arc surface 9 in a mirror symmetry manner.

A first boss plane 13 is connected between the first boss curved surface and the third boss curved surface, a second boss plane 14 is connected between the first boss curved surface and the second boss curved surface, and a third boss plane 15 is connected between the second boss curved surface and the third boss curved surface.

As shown in fig. 9 and 10, the inner side surface of the recess also has a first recess curved surface, a second recess curved surface and a third recess curved surface which are matched with each other, corresponding to the boss curved surface on the boss, and each recess curved surface is arranged like a mirror image of each boss curved surface and is positioned at the end part of the overall contour. The curved surfaces of the two bosses connected with the boss are different in plane structure, and the transition surface connecting the curved surfaces of the two adjacent recesses on the recess is still of a curved surface structure. Specifically, the first recess curved surface includes a first recess arc surface 23, and a first recess helical surface 260 and a first recess mirror helical surface 261 which are arranged in mirror symmetry along the first recess arc surface; the second concave seat curved surface comprises a second concave seat arc surface 24, a second concave seat spiral surface 270 and a second concave seat mirror image spiral surface 271, wherein the second concave seat spiral surface 270 and the second concave seat mirror image spiral surface 271 are arranged along the second concave seat arc surface in a mirror symmetry mode; the third pocket curved surface includes a third pocket arc 25, and a third pocket spiral 280 and a third pocket mirror spiral 281 arranged mirror-symmetrically along the third pocket arc. A first concave transition surface 29 is connected between the first concave curved surface and the third concave curved surface, a third transition curved surface 31 is connected between the third concave curved surface and the second concave curved surface, and a second transition curved surface 30 is connected between the first concave curved surface and the second concave curved surface. The helicoids on all the pockets have the same helical characteristics as the helicoids on the lands.

As shown in fig. 5, 6 and 8, the cutting head comprises a cutting portion 6, bosses 5 and counterbores 19 for receiving fastening screws, all helical surfaces and all mirror-image helical surfaces of the circumference of the bosses of the cutting head being symmetrically distributed about the boss axis, wherein the helical surfaces and the mirror-image helical surfaces in the curved surfaces of each boss are in turn mirror-symmetrical distribution two by two. One helicoid and mirror image helicoid in one boss curved surface are transitionally connected through the mode of arc surface rounding, for example, the first boss helicoid 100 and the first boss mirror image helicoid 101 in the first boss curved surface are transitionally connected through the first boss arc surface 7 in the rounding mode, and two boss curved surfaces are transitionally connected through a tangent plane, for example, the first boss curved surface and the third boss curved surface are transitionally connected through the first boss plane 13.

As shown in fig. 9, 10 and 11, the bracket has a recess 20 for the attachment of the boss 5 and a shank 21 designed as a tool holder for attachment to a machine tool. The concave seat 20 is provided with a helical surface corresponding to the convex seat 5, the helical surface has a helical characteristic with the convex seat on the same height in the axial direction, wherein, a first concave seat helical surface 260 and a first concave seat mirror image helical surface 261, a second concave seat helical surface 270 and a second concave seat mirror image helical surface 271, a third concave seat helical surface 280 and a third concave seat mirror image helical surface 281 are distributed in a mirror symmetry way in pairs, the first concave seat helical surface 260 and the first concave seat mirror image helical surface 261, the second concave seat helical surface 270 and the second concave seat mirror image helical surface 271, the third concave seat helical surface 280 and the third concave seat mirror image helical surface 281 are respectively in transition connection with tangent circular arc surfaces through a first concave seat arc surface 23, a second concave seat arc surface 24 and a third concave seat arc surface 25, in order to meet the good connection between the convex seat and the concave seat, the circular arc radii of the first concave seat arc surface 23, the second concave seat arc surface 24 and the third concave seat arc surface 25 are larger than those of the first convex seat arc surface 7, The arc radiuses of the second boss arc surface 8 and the third boss arc surface 9, meanwhile, transition surfaces on the concave seats corresponding to the first boss plane 13, the second boss plane 14 and the third boss plane 15 of the boss tangent plane are a first concave seat transition surface 29, a second concave seat transition surface 30 and a third concave seat transition surface 31 of an arc surface structure, when the convex seat is assembled, gaps are formed among the first concave seat transition surface 29, the second concave seat transition surface 30 and the third concave seat transition surface 31, the first boss plane 13, the second boss plane 14 and the third boss plane 15, the first concave seat transition surface 29, the second concave seat transition surface 30 and the third concave seat transition surface 31 and transition structures of adjacent spiral surfaces are small arc surfaces respectively, and the peripheral surface of each concave seat has the same taper angle with the peripheral surface of each boss along the axial direction. The boss floor 16 is not in contact with the pocket floor 32 after the cutting head is assembled with the carrier. In order to achieve effective back-chipping of the recess bottom of the recess, the recess bottom has a recess peripheral surface 35 with a cone angle of 0 °.

As shown in fig. 11 and 12, in order to make the bracket meet the mechanical requirements of cutting, the concave seat has a mirror symmetry center of a spiral surface which is in the same direction with the axial direction of the bracket handle, wherein the thinnest wall thickness h1 at the front end of the bracket is 30% of the radius of the inscribed circle of the cutting head, the thinnest wall thickness h2 at the upper end of the bracket is 45% of the radius of the inscribed circle of the cutting head, and the thinnest wall thickness h3 at the lower end of the bracket is 75% of the radius of the inscribed circle of the cutting head. In order to facilitate the finding of the height of the cutting tip during use, the cutting tip of the cutting portion of the cutting head is located on the extension of the edge of the cutting portion of the tool holder when the cutting head and the carrier are assembled.

During assembly, after the helical surface of the boss of the cutting head is approximately aligned with the helical surface of the concave seat, the boss is sent into the concave seat of the bracket along a common axis, after the screw is fastened, the helical surface on the boss and the helical surface on the concave seat are mutually attached and mutually extruded, and because all parts on the helical surface are in uniform contact, the helical surface is uniformly deformed, and when the modular cutter works, the stress of the helical surface is more uniform, the cutting effect is more stable, and the cutting vibration can be reduced.

As shown in fig. 4, 5, 6, 7 and 8, the helical surface on the projection, which is perpendicular to the axial direction, is represented in this plan view as a helix, wherein the radius of the major end of the helix is 84% of the radius of the inscribed circle of the cutting head, the radius of the minor end of the helix is about 74% of the radius of the inscribed circle of the cutting head, the helix angle range β is 39 °, and the helical surface is conically tapered in the axial direction, with the conical angle α preferably being 9 °.

All of the helicoids on the boss and all of the helicoids on the pocket satisfy the following formula: r_pSin θ ═ c (c is a constant and c > 0) -formula one;

on any cross section perpendicular to the central axis, the intersection line of the spiral pressure surface and the cross section is a cross section spiral line; the intersection point of the central axis on the cross section is the origin O of the cross section, and RP is the distance from any point P on the spiral line to the origin O; the position on the spiral line, which is farthest from the original point, is a large end A of the spiral line, and the distance from the large end of the spiral line to the original point is a large end radius RA; the position on the spiral line, which is the shortest from the original point, is a spiral line small end B, and the distance from the spiral line small end to the original point is a small end radius RB; the angle of the position angle [ AOP ] is beta, a tangent PM of the spiral line is made at a passing point P along the reverse direction of the preset rotating direction, a perpendicular PN of an OP is made at the passing point P along the reverse direction of the preset rotating direction, and the angle [ MPN ] is a helix lifting angle [ theta ];

the straight line of the spiral pressure surface on any section vertical to the spiral line of the cross section is a pressure spiral surface method section straight line; an included angle between the straight line of the normal section of the pressure spiral surface and the central axis is set as an inclination angle alpha, and when the opening of the inclination angle alpha points to one side of the boss, the inclination angle alpha is positive;

the first land spiral pressure surface and the first pocket spiral pressure surface have an inclination angle a of equal absolute value but opposite direction.

To demonstrate the benefits of a helical pressure surface that satisfies the above formula, the following is set forth:

first, the cross-sectional spiral on the helical pressure surface is defined as follows:

as shown in fig. 6, 7 and 8, in the cross section of the cutting head (the cross section of the bracket matches the cross section of the cutting head), the radial direction extends outwards by taking the first origin O as the center, and any radius OP is formed by any point P on the edge of the boss spiral pressure surface, namely the boss spiral line, and when the radius OP rotates by a slight angle d beta around the first origin O, obviously, the following radius:

dβ·R_p·tanθ＝dR_p

∵R_p·sinθ＝c

integration on both sides:

the above is the curvilinear polar equation of the outer edge of the convex stage helical pressure surface, i.e. the convex stage helical line, in the cross section. From this equation, it can be found that if c, R is determined_AAnd the variation range lambda of beta, can uniquely determine a section of the screwA spiral shape. Or, determine R_AR_BAnd the coverage angle AOB can calculate c, thereby uniquely determining the shape of the boss spiral line. Therefore, the shape of the spiral line can be determined by giving the diameter of the large end, the diameter of the small end and the position angle of the spiral line, or giving the value of c, the diameter of the large end, the inclination angle of the spiral line, or other equivalent conditions such as the spiral angle and the central position angle for determining the start-stop position, and the like, and the description is not repeated here.

Secondly, the arbitrary cross section of the whole spiral pressure surface is the same shape

In the axial direction, two different cross sections are selected axially at a distance L from each other across the helical pressure surface. It is assumed that the first cross-sectional spiral of the first cross-section satisfies the formula one. In the normal plane of the spiral pressure surface, the spiral pressure surface extends in a straight line which forms an angle alpha with the axial direction, and the two cross sections are parallel, so that the spiral pressure surface with the second cross section is obtained by extending the first cross section spiral of the first cross section in the normal plane along a straight line which forms the same angle with the axial line by the same axial height L; therefore, the projection of the second cross-sectional spiral in the second cross-section in the first cross-section is in a normal offset relationship with the first cross-sectional spiral, and the normal distance is L · tan α. As long as it is proved that the second cross-section spiral also satisfies the formula one, it is stated that all cross-sections of the spiral pressure surface in the present embodiment satisfy the formula one. It is demonstrated below that the second cross-sectional spiral also satisfies the formula one.

Observing in the first cross section, 0 is a central point, projecting the second cross section spiral line into the cross section, and regarding any point P on the first cross section spiral line₁A corresponding point P can be found on the projected second cross section spiral₂Let P stand₁P₂Perpendicular to the first cross-sectional spiral and the second cross-sectional spiral, respectively. Setting OP₁Length R₁，OP₂Length R₂. Per P₁、P₂Respectively making tangent lines P of helical lines of respective cross section₁M₁、P₂M₂. Per P₁、P₂Perpendicular lines P with respective radius₁N₁、P₂N₂. Over 0 to P₁P₂The foot is Q.

∵∠QP₁O＝∠M₁P₁N₁And is < QP₂O＝∠M₂P₂N₂

∴R₁·sin∠M₁P₁N₁＝R₁·sin∠QP₁O＝OQ

And R is₂·sin∠M₂P₂N₂＝R₂·sin∠QP₂O＝OQ

∴R₁·sin∠M₁P₁N₁＝R₂·sin∠QP₂O＝c(c＞0)

The above results indicate that the formula one is satisfied and that the c values are the same on the cross sections of different axial positions on the above-described helical pressure surface.

Thirdly, explaining the characteristics of any cross section on the spiral pressure surface when rotating

The cutting head and the carrier in this solution are coupled, viewed in a section perpendicular to the centre axis. Assuming that the cutting head is rotated by a slight angle d β about the first origin O with respect to the carrier, and the original point P is moved to the point P1, the point P is displaced S in the circumferential direction₁＝R_pD β. This displacement is resolved orthogonally to the tangential and normal directions of the cross-sectional spiral (boss spiral on boss, pocket spiral on pocket). On the one hand, the component S of this displacement in the tangential direction of the cross-sectional helix₁₁＝S₁Cos θ ═ c · cot θ · d β; on the other hand, the component S of the displacement in the normal direction of the cross-sectional helix₁₂＝S₁sin θ is c · d β. It can be seen that the component in the normal direction of the cross-section spiral is independent of β, which means that when the cross-section spiral is in rotational motion, the motion speed of any point on the cross-section spiral along the normal direction of the cross-section spiral at the position where the point is equal.

Viewed in a cross-section perpendicular to the central axis. Assume that the cutting head is rotated about the first origin O by a large angle Δ β relative to the carrier. Setting the distance between the newly obtained rotated boss spiral line and the original boss spiral line as delta w, and including:

the above formula shows that, under the condition of not considering the length of the cross-section spiral line, the cross-section spiral line rotates around the center by delta beta, the normal distance between the newly obtained cross-section spiral line and the original cross-section spiral line is equal everywhere, and the linear relation exists between the rotation angle delta beta and the distance difference delta w.

Fourthly, explaining the characteristics of the whole spiral pressure surface when rotating

When the cutting head is rotated by delta beta relative to the carrier, the displacement of each point of the helical pressure surface along the normal direction of the helical line is delta w in the cross section. Setting the normal displacement of each point along the helicoid at the position as delta h

Δh＝cosα·Δw＝cosα·c·Δβ

During rotation, delta h at any beta position is the same, and the delta h and the delta beta are in a linear relation; when the boss spiral pressure surface of the cutting head is matched with the two pressure surfaces of the concave seat spiral pressure surface of the bracket, the two pressure surfaces are in simultaneous contact; the compression amount of each point is uniform during extrusion. In addition, during manufacturing, the outer circle of the milling cutter or the grinding wheel is usually tangent to the spiral line to move, the error of the diameter of the grinding wheel or the diameter of the milling cutter only causes the deviation of the spiral line in the normal direction, the deviation of the normal direction does not affect the shape of the spiral line in the scheme, and only the influence of a certain rotation angle is generated, which can be easily seen from the above description.

Five, basic force analysis

In the present case, the range of the angle of inclination α is selected to be implemented in the interval of [ -30 °, -8 ° ] and [8 °, 30 ° ], preferably 9 ° and-9 °. Within the range, alpha is small, and the self-locking type torque transmission device has strong torque transmission capacity and radial positioning capacity and cannot form self-locking.

As already explained above, the normal deformation of the points on the pressure surface of the screw is the same in the case of a rotational pressing displacement. Assuming that the elastic modulus of each point is the same, the positive pressure of each point is the same. The cutting head is taken as a research object, the pressure per unit area on the pressure surface of the spiral is m, a point P is selected on the pressure surface optionally, a tiny range is selected in the area of the point P, the size of the range on a section perpendicular to the spiral line is dh, the size on the cross section (along the spiral line) is dl, and the positive pressure F at the point P is m.dl.dh.

Decomposing said positive pressure, component F in axial direction_aM · dl · dh · sin α; component F in cross section_h＝m·dl·dh·cosα。

The component direction on the cross section is perpendicular to the spiral line, and the spiral line is divided into radial component F and circumferential component F_hr＝cosθ·F_hComponent of the circumferential direction F_hc＝sinθ·F_h。

I.e. the positive pressure F is finally decomposed into an axial component F_aRadial component F_hrA circumferential component F_hc。

In summary, a slight positive pressure on the spiral pressure surface is represented as:

axial traction force: f_a＝sinα·m·dl·dh。

Radial force: f_hr＝cosθ·cosα·m·dl·dh。

Circumferential force: f_hc＝sinθ·cosα·m·dl·dh。

Sixthly, balance of torque

The traditional concept is that: such surfaces, each at a relatively large angle to the radius, while having good radial retention, often fail to transmit relatively large torques. This is because general structures such as straight lines, eccentric arcs, archimedes' spirals, etc. are unevenly stressed at various positions during torque transmission, and only local areas act on the entire surface, causing a dangerous point to be formed prematurely and reducing the stress range; resulting in a loss of torque transmitting capability or a loss of radial holding capability.

The problem of atress inhomogeneous has been solved to the structure of this scheme to under the condition that does not increase length, increased the lifting surface area, thereby increased the moment of torsion transmissibility. And the whole spiral line area is contacted, the distribution range of the radial retaining force is expanded, and the radial retaining capacity is improved.

An analog estimation of torque transfer capability is made as follows. Since the case is substantially the same for each range of dh heights, the torque that a helical pressure face positive pressure can provide for a single dh range is described here, i.e. without integrating dh:

T_n＝∫F_hc·R＝∫m·dh·dl·cosα·sinθ·R

∵dl·sinθ＝dR

∴T_n═ m · dh · cos α · R · dR ═ m · dh · cos α · ═ R · dR ═ di ═ m · dh · cos α · ═ R · dR ═ di

According to the second expression and the third expression, the torque provided by the surface positive pressure of the structure disclosed by the scheme is equivalent to the torque provided by the torque surface which has the same radius variation and extends along the radius in a straight line. The latter is often referred to as a torque transmitting structure and thus can be analogized. In addition, the static friction force of each point of the structure of the scheme can also play a role in transmitting torque. The structure of the scheme can completely provide enough torque.

Of course, if the structure of the present solution is mainly designed to transmit torque, α should take a smaller absolute value.

And seventhly, axial traction is provided during assembly.

The helical pressure surface exhibits excellent axially stable traction in the axial direction. When the cutting head is assembled, the cutting head rotates around the axis relative to the bracket, corresponding spiral pressure surfaces almost simultaneously contact with each other, and simultaneously compress, so that the cutting head is prevented from warping and skewing in the whole process, and stable traction characteristics are presented.

The rotation angle is linear with the axial traction force. The structure is easy to form a pressure fit with other axial positioning structures, and preferably can form self-locking.

The following integral describes the sum of the forces acting on all areas of the screw pressure surface. In practice, assuming that the positive pressure per unit area is m, the torque generated by the positive pressure over the entire helical pressure surface is m

T_n＝∫∫m·dh·dl·cosα·sinθ·R＝∫∫m·c·dh·dl·cosα·sinθ

While the torque of the friction force generated by the positive pressure on the helicoid is

The axial force itself does not generate a torque, but at the positioning surface in the axial direction, a positive pressure is generated due to the axial force, thereby generating a frictional torque. Assuming that the friction coefficients are the same, the positive pressure generated by the axial force on other surfaces is n times of the axial force, the torque radius is r, and the friction torque generated by the axial force on other structures is

T_fa＝∫∫n·r·μ·sinα·m·dl·dh

The parameters n, r, alpha and the parameters of the cross-sectional spiral are preferably designed such that

Self-locking can be realized. In practice, the above integrals can be optimized by numerical solution in a discrete point manner.

The rotational movement and the axial movement can be converted into each other because of the presence of the helical pressure surface.

Example two

In the present embodiment, an inner space is opened in the boss provided on the boss spiral pressure surface or in the pocket provided on the pocket spiral pressure surface, and a rotating body that can rotate in the inner space is placed in the inner space. With the rotation of the boss or the recess, the rotating force received on the spiral pressure surface of the boss or the spiral pressure surface of the recess can be transmitted to the inner space and becomes the rotating power of the rotating body in the inner space, so that the torque transmission force received on the spiral pressure surface of the boss or the spiral pressure surface of the recess is reduced, and the condition that local abrasion is caused by uneven stress possibly occurring on each spiral pressure surface is reduced.

EXAMPLE III

In the embodiment, in the boss arranged on the spiral pressure surface of the boss or the recess arranged on the spiral pressure surface of the recess, an inner space is arranged in the boss, the inner space is provided with a through hole communicated with the spiral pressure surface and communicated with an air pipe capable of injecting air outwards through the inner space, and the spiral pressure surfaces which are stressed in an interference mode in rotation are pushed through the air pipe to form thrust to reduce the abrasion between the two spiral pressure surfaces in a through hole air injection mode, so that the stress on each spiral pressure surface is balanced, and the condition that local abrasion is caused by uneven stress possibly occurring on each spiral pressure surface is reduced.

The above description is only for the embodiments of the present invention, and the common general knowledge of the known specific structures and characteristics in the schemes is not described herein too much, and those skilled in the art will know all the common technical knowledge in the technical field of the present invention before the application date or the priority date, can know all the prior art in this field, and have the ability to apply the conventional experimental means before this date, and those skilled in the art can combine their own ability to perfect and implement the schemes, and some typical known structures or known methods should not become obstacles for those skilled in the art to implement the present application. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. A modular turning tool is characterized by comprising a cutting head and a bracket which are matched, wherein a boss is arranged at one end of the cutting head close to the bracket, and a recess is arranged at one end of the bracket close to the cutting head; the inner surface of the concave seat is matched with the shape of the outer surface of the boss; the boss is provided with a boss axis, a plurality of boss end parts are symmetrically arranged on the outer surface of the boss along the boss axis, and a tangent plane is connected between every two adjacent boss end parts; the concave seat is provided with a concave seat axis, a plurality of concave seat ends are symmetrically arranged on the inner surface of the concave seat along the concave seat axis, and a transition curved surface is connected between every two adjacent concave seat ends; the inner surface of the socket end matches the outer surface of the boss end; the pocket axis and the boss axis are coaxial to form a common axis when the pocket is connected with the boss; each boss end part comprises a boss spiral surface and a boss mirror image spiral surface which are arranged in mirror symmetry relative to a plane passing through the boss axis; each pocket end comprises a pocket helicoid and a pocket mirror helicoid arranged mirror-symmetrically with respect to a plane passing through the pocket axis.

2. The modular lathe tool according to claim 1, wherein a boss arc surface is connected between the boss helicoid and the boss mirror image helicoid; and a concave seat arc surface is connected between the concave seat spiral surface and the concave seat mirror image spiral surface.

3. The modular lathe tool of claim 1, wherein all helicoids and mirror helicoids satisfy the following helical pressure surface formula: r_pSin θ ═ c, c is a constant and c > 0;

on any cross section perpendicular to the central axis, the intersection line of the spiral pressure surface and the cross section is a cross section spiral line; the intersection point of the central axis on the cross section is the origin O of the cross section, and RP is the distance from any point P on the spiral line to the origin O; the position on the spiral line farthest from the original point is a big end A of the spiral line, and the distance from the big end of the spiral line to the original point is a big end radius R_A(ii) a The position on the spiral line, which is the shortest from the original point, is a spiral line small end B, and the distance from the spiral line small end to the original point is a small end radius R_B(ii) a The angle of the position angle AOP is beta, and the passing point P is from the small end to the large end of the helixMaking a perpendicular line PN of an OP (operational noise) along the direction from the small end to the large end of the helix at a passing point P to a tangent PM of the helix, wherein the angle MPN is a helix lift angle theta;

4. A modular turning tool according to claim 3, characterised in that the absolute value of the angle of inclination α is 9 ° and the coverage of the position angle β is 39 °.

5. The modular lathe tool of claim 3, wherein the major end diameter of the boss cross-section spiral is 84% of the diameter of the cutting head inscribed circle, and the minor end diameter of the boss cross-section spiral is 74% of the diameter of the cutting head inscribed circle.

6. The modular lathe tool of claim 1, wherein the transition curved surface is a small arc surface.

7. The modular turning tool according to claim 1, wherein the pocket peripheral surface has the same inclination angle in the axial direction as the boss peripheral surface.

8. The modular lathe tool of claim 1, wherein a clearance is provided between a bottom surface of the boss and a bottom surface of the pocket when the cutting head is coupled to the carriage up and down.

9. The modular lathe tool of claim 5, wherein the groove bottom of the pocket has a circumferential surface with an inclination angle of 0 °.

10. The modular lathe tool according to claim 1, wherein an inward concave surface is connected between the boss spiral surface and the boss mirror-image spiral surface; and an arc transition surface is connected between the concave seat spiral surface and the concave seat mirror image spiral surface.