A clamping tool for steel sleeve of injection molding machine

Abstract

The present application discloses a clamping tool for a steel sleeve of an injection molding machine, which is installed at the front end of a lathe spindle. The clamping tool comprises a three-jaw chuck and a positioning assembly. The three-jaw chuck is detachably installed at the front end of the lathe spindle. The three-jaw chuck has a clamping claw, which is suitable for clamping the outer side of the steel sleeve. The steel sleeve is suitable for being sleeved on the outer side of the positioning assembly. The positioning part is suitable for being detachably fixed on the front side of the three-jaw chuck, and limiting the misalignment angle of the virtual triangle formed by the steel sleeve and the clamping claw along the axial direction to α+180°. One purpose of the present application is to facilitate the processing and forming of a clamping tool for a steel sleeve with high forming precision.

Description

Technical Field

[0001] The present application relates to the field of steel sleeves, and in particular to a steel sleeve for an injection molding machine and a clamping tool thereof. Background Art

[0002] At present, the steel sleeve of the injection molding machine is mainly installed on the tie rod or injection guide rod to reduce the friction generated when the movable platen or injection component slides on the tie rod or injection guide rod. Due to the large weight of the movable platen or injection component, for conventional injection molding machine models (such as clamping force 136t-280t), the weight of the movable platen or injection component exceeds 500kg. During repeated use, the wear and durability of the steel sleeve has a great impact on the overall stability and repeatability of the injection molding machine. Especially for scenes with high requirements for mold opening and closing precision, it is necessary to ensure that the force at each position of the mold is uniform. In addition to ensuring the flatness between the movable platen and the fixed platen in static state, it is also necessary to ensure that the force of the four steel sleeves at the connection between the movable platen and the tie rod is uniform during dynamic movement. If the precision of individual steel sleeves is poor, it will have a great impact on the service life of the tie rod and its use in high-precision scenes.

[0003] However, the existing steel sleeves have a slow processing speed and poor precision during processing, which is a problem that needs to be solved by those skilled in the art. Summary of the invention

[0004] One purpose of the present application is to provide a steel sleeve with fast processing speed and high precision.

[0005] Another object of the present application is to facilitate the processing and forming of a clamping tool for a steel sleeve with high precision.

[0006] In order to achieve the above objectives, the technical solution adopted in this application is:

[0007] A clamping tool for a steel sleeve of an injection molding machine, installed at the front end of a lathe spindle, the clamping tool comprising a three-jaw chuck and a positioning assembly, the three-jaw chuck being detachably installed at the front end of the lathe spindle, the three-jaw chuck having a clamping jaw, the clamping jaw being suitable for clamping the outer side of the steel sleeve, the steel sleeve being suitable for being sleeved on the outer side of the positioning assembly; during a clamping operation, the three-jaw chuck is suitable for clamping the front side of the steel sleeve, the positioning assembly is suitable for being detachably fixed to the rear side of the steel sleeve, and the positioning assembly extends axially backward A positioning portion is formed, which is suitable for indicating that the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws of the three-jaw chuck is α during the first clamping; during the second clamping, the positioning assembly is kept detachably fixed to the inside of the rear side of the steel sleeve and the steel sleeve is turned, and the three-jaw chuck is suitable for clamping the outside of the rear side of the steel sleeve, and the positioning portion is suitable for being detachably fixed to the front side of the three-jaw chuck, and limiting the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws to α+180°.

[0008] The inventor of the present invention has found that the existing injection molding machine is very prone to the problem of tie rod breakage under the working conditions of high clamping pressure, high precision and high speed. Although methods such as increasing the tie rod diameter and replacing the tie rod material can help to improve the service life of the tie rod, long-term use (continuous use for more than one year) still easily leads to the problem of tie rod breakage. After further research, the inventor found that the tie rod breakage is largely due to the uneven force of the four tie rods on the dynamic template of the injection molding machine. When the injection molding machine is in a static environment, the flatness between the dynamic template and the fixed template can be easily corrected by using a flatness measuring tool. However, in actual use, it is found that in the working environment of the injection molding machine, the dynamic template moves back and forth along the axis direction of the tie rod, and the flatness between the dynamic template and the fixed template will also change, and this change is difficult to be later repaired and adjusted by general adjustment means. The reason is mainly that the contact position between the dynamic template and the tie rod (that is, the position where the steel sleeve is located) is unevenly stressed, and the dynamic template is deformed, so that the tie rod is subjected to greater dynamic impact during the movement of the dynamic template, resulting in tie rod breakage, and the tie rod breakage caused by this factor is difficult to solve by increasing the thickness of the tie rod.

[0009] Further research found that the uneven force on the steel sleeve was due to the problem of roundness of the steel sleeve after processing on the centerless grinder, and because there was an interference fit between the steel sleeve and the moving template (generally, the steel sleeve was cooled with liquid nitrogen before installation), the steel sleeve that shrank and then expanded again deformed irregularly in the steel sleeve mounting hole on the moving template, resulting in different force conditions at different positions, resulting in uneven and irregular contact positions between the four steel sleeve mounting holes of the moving template and the pull rod, which can easily cause the pull rod to break or even the template to break after long-term use.

[0010] The inventor's first idea was to change the processing technology and use an external cylindrical grinder to process the steel sleeve to reduce the possibility of edge roundness. However, the processing speed of the external cylindrical grinder is slow and cannot meet the needs of large-scale processing. In addition, the straightness of the axis is also poor. The main reason is that the external cylindrical grinder relies on the inner diameter of the steel sleeve for positioning. The inner diameter has not been finely ground, and the positioning itself is not accurate enough, resulting in poor precision of the formed steel sleeve and low processing efficiency.

[0011] The traditional method of improving the roundness of the centerless grinder is to increase the height of the bracket and use the characteristics of the centerless grinder to repair the roundness of the edges. However, this method will increase the ellipse of the steel sleeve and is not conducive to the production of high-precision steel sleeves. In addition, the problem of roundness of the steel sleeve when processed by the centerless grinder is that the steel sleeve is clamped by the three-jaw chuck in the pre-processing process (lathe grooving), resulting in a triangular round edge after processing, and this triangle will not be eliminated in the processing process of the centerless grinder.

[0012] Therefore, the inventor has developed a new processing method, which uses the clamping force of the three-jaw chuck and the cutting effect of the lathe to make the front and rear sides of the steel sleeve present a centrally symmetrical triangular prism (the front and rear sides present a central symmetry, which means that the projections of the front side surface of the steel sleeve and the rear side surface of the steel sleeve on the cross section are centrally symmetrical relative to the projection point of the axis of the steel sleeve on the cross section), so that the steel sleeve can be processed by the centerless grinder in the subsequent centerless grinder. The roundness of the prism can be repaired, thereby achieving the production of steel sleeves with higher precision. It is worth mentioning that although the use of a four-point chuck can also be used to repair the prism in the subsequent centerless grinder, the four-point chuck has poor centering ability, a complicated clamping process, poor practicality, and is inconvenient to use. It is not applicable in conventional mass production, and the processing process is slow, and it cannot be connected to the subsequent automatic clamping and automatic production system, resulting in the inability to reduce the processing cost.

[0013] In order to form a steel sleeve with front and rear sides presenting a centrally symmetrical triangle, the inventor further developed a clamping tool with a positioning component. During the first clamping, the positioning component is fixed to the rear side of the steel sleeve, and the positioning part is used to indicate that the virtual triangle formed by the steel sleeve and the clamping jaws has an axial misalignment angle of α. During the second clamping, since the positioning part is detachably connected to the three-jaw chuck, the positioning part can be used to achieve an axial misalignment angle of α+180° for the virtual triangle formed by the steel sleeve and the clamping jaws, thereby achieving that during the two clamping processes, the clamping positions can be 180° centrally symmetrical, so that the front and rear sides of the steel sleeve present a centrally symmetrical triangle, which is convenient for subsequent entry into the centerless grinder and subsequent centerless grinding operations.

[0014] It is worth mentioning that there are many ways to use the positioning part to indicate the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws, such as using the shape of the positioning part (such as an arrow shape) to make the direction of the arrow point to the direction of one of the clamping jaws, thereby ensuring that during the second clamping, the arrow direction can point to the 180° rotation direction of the clamping jaw. The detachable mounting method of the positioning component and the steel sleeve can be magnetic, and the detachable mounting method of the positioning part and the three-jaw chuck can also be magnetic, so that the positioning component can be controlled relative to the steel sleeve. The angle of the virtual triangle formed by the positioning part and the clamping jaws is controlled without rotating, so that the virtual triangles formed by the clamping jaws during the two clamping processes are mutually displaced by 180° in the axial direction.

[0015] The positioning part on the positioning assembly is used to indicate the axial misalignment angle between the deformed steel sleeve and the clamping jaw when the steel sleeve is clamped once, and the positioning part is used to achieve the axial misalignment angle of the steel sleeve and the clamping jaw to be α+180°, so that the steel sleeve is easier to form a centrally symmetrical triangular prism on the front and back sides, the processing speed is faster, the installation is easier, and the operation difficulty is lower.

[0016] In addition, although the front and rear sides of the steel sleeve can be made triangular in shape through reverse clamping, it is difficult to ensure that the triangular edges on the front and rear sides are centrally symmetrical triangles due to the lack of a positioning device. If the axial misalignment angle of the triangular edges on the front and rear sides is small, the centerless grinder cannot be used to repair the roundness of the edges, resulting in poor repetition accuracy of the formed steel sleeve and uneven force on the same moving template (four steel sleeves). Therefore, the purpose of improving the roundness of the steel sleeve edges cannot be achieved.

[0017] Further preferably, the clamping tool also includes an auxiliary component, the steel sleeve is arranged on the outside of the auxiliary component, and during a clamping operation, the rear end of the auxiliary component is suitable for being detachably mounted on the front end of the three-jaw chuck, and the front end of the auxiliary component is detachably connected to the inside of the rear side of the steel sleeve, and the auxiliary component is suitable for controlling the axial misalignment angle of the virtual triangle composed of the steel sleeve and the clamping jaws during a clamping operation, and the positioning component is suitable for performing rough positioning through the auxiliary component and determining the axial misalignment angle of the virtual triangle composed of the positioning component and the clamping jaws.

[0018] Further preferably, the positioning portion is a polygonal column, the side edges are parallel to the axis and the number of side edges is 3n (n is a positive integer and an odd number), an auxiliary positioning portion is arranged on the outside of the auxiliary component, the shape and size of the auxiliary positioning portion are the same as those of the positioning portion, and the auxiliary positioning portion and the projection of the positioning portion on the cross section are centrally symmetrical with respect to the projection point of the axis on the cross section, the front end of the three-jaw chuck is provided with a mounting groove matching the positioning portion, and the positioning component and the auxiliary component are suitable for being detachably connected to the front end of the three-jaw chuck through the mounting groove.

[0019] Further preferably, the positioning portion is in the shape of a triangular prism, the cross-sectional shape of the mounting groove is a triangle matching the positioning portion, and is axially offset by 180° with a virtual triangle formed by the clamping jaws in the clamping state, and when the positioning portion or the auxiliary positioning portion is installed in the mounting groove, there is a gap between the groove wall of the mounting groove and the outer wall of the positioning portion or the auxiliary positioning portion.

[0020] Further preferably, an auxiliary limiting portion is radially arranged outwardly on the auxiliary component, the auxiliary limiting portion is made of elastic material, the outer wall of the auxiliary limiting portion is suitable for contacting the inner wall of the mounting hole on the steel sleeve, and the auxiliary component is suitable for being detachably connected to the steel sleeve through the auxiliary limiting portion; the positioning component comprises a connecting rod and a limiting portion, the connecting rod extends along the axial direction of the positioning component, and a triangular positioning pin is arranged at the rear end of the connecting rod, a positioning hole matching the positioning pin is arranged at the front end of the auxiliary component, the connecting rod is detachably fixed to the front end of the auxiliary component through the positioning pin and the positioning hole, the front end of the connecting rod is fixed on the positioning component, the connecting rod is suitable for roughly positioning the relative positions of the positioning component and the auxiliary component along the axial direction, the limiting portion is radially arranged outwardly on the outside of the positioning component, the limiting portion is made of elastic material, the outer wall of the limiting portion is suitable for contacting the inner wall of the mounting hole on the steel sleeve, and controlling the rotation angle of the positioning component and the steel sleeve, and the positioning portion is arranged on the front side of the limiting portion.

[0021] Further preferably, the auxiliary component is provided with a plurality of auxiliary limiting portions protruding radially outward, the auxiliary limiting portions are made of elastic material, and the auxiliary limiting portions are suitable for invading the lubrication holes circumferentially arranged on the rear side of the steel sleeve and limiting the relative rotation between the steel sleeve and the auxiliary component; the positioning component is provided with a plurality of limiting portions protruding radially outward, the limiting portions are made of elastic material, and the limiting portions are suitable for invading the lubrication holes circumferentially arranged on the front side of the steel sleeve and limiting the relative rotation between the steel sleeve and the positioning component.

[0022] Further preferably, the positioning assembly includes a connecting column, the steel sleeve is arranged on the outside of the connecting column, the connecting column extends axially and forms a deformation bowl, the bottom of the deformation bowl is connected to the connecting column, the outer bowl wall of the deformation bowl is projected as a concave curve in the longitudinal section, and a plurality of limiting portions are provided on the outer wall of the bowl mouth of the deformation bowl protruding radially outward, and the limiting portions are circumferentially arranged on the outer wall of the deformation bowl. During one clamping, the deformation bowl and the connecting column successively invade the mounting hole of the steel sleeve axially backward, and at this time, the connecting column continues to be driven axially backward to deform the deformation bowl, and the limiting portion and the steel sleeve are put into a locked state.

[0023] Further preferably, the auxiliary component includes an auxiliary connecting column, the steel sleeve is arranged on the outside of the auxiliary connecting column, the auxiliary connecting column extends axially and forms an auxiliary deformation bowl, the bottom of the auxiliary deformation bowl is connected to the auxiliary connecting column, and a plurality of auxiliary limiting parts are radially protruding outward on the outer wall of the bowl mouth of the auxiliary deformation bowl, and the auxiliary limiting parts are circumferentially arranged on the outer wall of the auxiliary deformation bowl. During one clamping, the auxiliary connecting column and the auxiliary deformation bowl are sequentially axially invaded into the mounting hole of the steel sleeve. At this time, the auxiliary connecting column is continued to be driven axially forward to deform the auxiliary deformation bowl, and the auxiliary limiting part and the steel sleeve are put into a locked state.

[0024] Further preferably, the bowl mouths of the deformable bowl and the auxiliary deformable bowl protrude radially outward respectively and are circumferentially surrounded by a bearing portion and an auxiliary bearing portion, the limiting portion and the auxiliary limiting portion are radially protrudingly arranged on the bearing portion and the auxiliary bearing portion respectively, the bearing portion and the auxiliary bearing portion are made of elastic material, and the outer walls of the bearing portion and the auxiliary bearing portion are suitable for contacting the inner wall of the mounting hole of the steel sleeve; the connecting column and the auxiliary connecting column are made of rigid material, and there is a gap between the outer walls of the connecting column and the auxiliary connecting column and the steel sleeve.

[0025] A steel sleeve for an injection molding machine made of the above clamping tooling, wherein the lubrication holes on the steel sleeve are arranged radially and connected to the mounting holes of the steel sleeve, the lubrication holes are circumferentially arranged and axially arranged on the steel sleeve, the number of the lubrication holes arranged in the axial direction is 2x rows (x is a positive integer), and the number of the lubrication holes distributed circumferentially is 3y (y is a positive integer).

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] (1) The positioning part on the positioning assembly indicates the axial misalignment angle between the deformed steel sleeve and the virtual triangle formed by the clamping jaws during the first clamping of the steel sleeve, and the positioning part is used to realize the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws to be α+180°, so that the steel sleeve is easier to form a centrally symmetrical triangular prism on the front and back sides, which is faster in processing speed, easier to install, and less difficult to operate;

[0028] (2) During the first clamping, since the positioning part is arranged on the front side of the steel sleeve, it is easier to observe with the naked eye or use other visual aids to make the axial misalignment angle α of the virtual triangle formed by the positioning part and the clamping jaws easier to identify, so that during the second clamping, the axial misalignment angle of the virtual triangle formed by the positioning part and the clamping jaws is maintained at α+180°, so that the steel sleeve is processed and formed into a triangular prism with symmetry on the front and rear sides, which is convenient for the subsequent automatic repair of the prism roundness by centerless grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of a steel sleeve for an injection molding machine according to the present application.

[0030] Figure 2 It is a front view of the clamping jaws of the clamping tool of the present application, showing the virtual triangle formed by the clamping jaws.

[0031] Figure 3 This is a schematic diagram of the clamping process of the present application when the steel sleeve is clamped, and at this time the steel sleeve does not deform.

[0032] Figure 4 This is a schematic diagram of the clamping process of the present application when clamping the steel sleeve, at which time the steel sleeve is a triangular shaped rounded shape.

[0033] Figure 5 This is a schematic diagram of a conventional centerless grinder processing a circular steel sleeve.

[0034] Figure 6 This is a schematic diagram of the conventional method of using a centerless grinder to repair edge roundness.

[0035] Figure 7 This is a schematic diagram of the rounded steel sleeve after lathe processing in this application.

[0036] Figure 8 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing the positioning portion.

[0037] Fig. 9 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing the position of the positioning part during secondary clamping.

[0038] Fig.10 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing an auxiliary positioning component.

[0039] Fig.11 This is a schematic diagram of a cross section of an embodiment of the clamping tool of the present application, showing the relative positions of the positioning portion and the auxiliary positioning portion.

[0040] Fig.12 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing that the auxiliary positioning portion is installed in the installation groove.

[0041] Fig.13 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing the gap between the auxiliary positioning portion and the mounting groove.

[0042] Fig.14 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing a method of coarse positioning.

[0043] Fig.15 This is a schematic diagram of an embodiment of the clamping tool of the present application, showing a connecting rod and a locating pin.

[0044] Fig.16 It is a cross-sectional view of an embodiment of the clamping tool of the present application.

[0045] Fig.17 This is a partial enlarged view of the B position of an embodiment of the clamping tool of the present application, showing an auxiliary limiting portion.

[0046] Fig.18 This is a schematic diagram of another embodiment of the clamping tool of the present application, showing another rough positioning method.

[0047] Fig.19 It is a cross-sectional view of another embodiment of the clamping tool of the present application.

[0048] Fig. 20 This is a partial enlarged view of the C position of another embodiment of the clamping tool of the present application, showing the auxiliary bearing part.

[0049] Fig.21 It is a partial enlarged view of the D position of another embodiment of the clamping tool of the present application, showing the bearing part.

[0050] Fig. 22 A partial cross-sectional view of another embodiment of the clamping tool of the present application shows a deformed bowl.

[0051] Fig.23 This is a partial enlarged view of the undeformed C position of the deformation bowl of another embodiment of the clamping tool of the present application.

[0052] Fig.24 It is a schematic diagram of further driving the deformation bowl of another embodiment of the clamping tool of the present application.

[0053] Fig.25 This is a partial enlarged view of the deformed C position of the deformable bowl of another embodiment of the clamping tool of the present application.

[0054] In the figure: 1. three-jaw chuck; 11. clamping jaws; 12. mounting groove; 2. positioning assembly; 21. positioning part; 211. locking part; 22. limiting part; 23. connecting rod; 231. positioning pin; 24. connecting column; 25. deformation bowl; 251. bearing part; 252. outer bowl wall; 3. auxiliary assembly; 31. auxiliary positioning part; 32. auxiliary limiting part; 33. auxiliary connecting column; 34. auxiliary deformation bowl; 341. auxiliary bearing part; 35. positioning hole; 100. steel sleeve; 101. lubrication hole; 102. annular groove; 103. axial groove; 104. mounting hole; 105. A side; 106. B side; 200. guide wheel; 300. grinding wheel; 400. bracket. DETAILED DESCRIPTION

[0055] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0056] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present application.

[0057] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0058] The terms "including" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0059] The inventor of the present invention found that the existing injection molding machine is very prone to tie rod breakage under high clamping pressure, high precision and high speed conditions. Although increasing the tie rod diameter and replacing the tie rod material can help to increase the service life of the tie rod, long-term use (continuous use for more than one year) is still prone to tie rod breakage. After further research, the inventor found that tie rod breakage is largely due to uneven force on the four tie rods on the dynamic mold plate of the injection molding machine. When the injection molding machine is in a static environment, the flatness measurement tool can be used to easily correct the uneven force between the dynamic mold plate and the fixed mold plate. However, in actual use, it is found that when the movable platen moves back and forth along the axis of the tie rod in the working environment of the injection molding machine, the flatness between the movable platen and the fixed platen will change, and this change is difficult to be repaired and adjusted later by general adjustment means. The main reason is that the contact position between the movable platen and the tie rod (that is, the position of the steel sleeve 100) is unevenly stressed, and the movable platen is deformed, which causes the tie rod to withstand greater dynamic impact during the movement of the movable platen, causing the tie rod to break. Moreover, the tie rod breakage caused by this factor is difficult to solve by increasing the thickness of the tie rod.

[0060] Further research found that the uneven force on the steel sleeve 100 was due to the problem of edge roundness of the steel sleeve 100 after processing on the centerless grinder, and since there was an interference fit between the steel sleeve 100 and the moving template (generally, the steel sleeve 100 is installed after being cooled by liquid nitrogen), the steel sleeve 100 that shrank and then expanded again deformed irregularly in the steel sleeve mounting hole on the moving template, resulting in different force conditions at different positions, which resulted in uneven and irregular contact positions between the four steel sleeve mounting holes of the moving template and the pull rod, which could easily cause the pull rod to break or even the template to break after long-term use.

[0061] Steel sleeve 100 Figure 1 As shown, a lubrication hole 101 is provided, and an annular groove 102 and an axial groove 103 are also provided. A mounting hole 104 is provided along the axial direction for mounting a pull rod or an injection guide rod. Generally, the blank is formed by forging, and the traditional processing technology is as follows:

[0062] S1: peeling the blank by lathe; S2: forming the lubrication hole on the steel sleeve 100 by drilling machine; S3: forming the axial groove 103 on the steel sleeve 100 by milling machine; S4: finishing by lathe and forming the annular groove 102 on the steel sleeve 100; S5: electroplating; S6: machining the outer circle by centerless grinder; S7: machining the inner circle by internal grinder with the outer circle as reference.

[0063] The reason why the steel sleeve 100 has rounded edges is mainly because in step S4, a certain rounded edge is formed by lathe processing, which causes the subsequent centerless grinder to be unable to eliminate the rounded edge under certain circumstances due to the characteristics of the centerless grinder, resulting in the steel sleeve 100 having rounded edges, as follows:

[0064] Since the lathe generally adopts a three-jaw chuck 1 for clamping, the three clamping jaws 11 of the three-jaw chuck 1 will form a virtual triangle, such as Figure 2 As shown by the dotted line, under the clamping of the clamping jaws 11 and the turning action of the lathe, the steel sleeve 100 will have rounded edges. Figure 3 The figure shows the positional relationship between the clamping jaw 11 and the steel sleeve 100 in the unclamped and unprocessed state; Figure 4 It is shown that after clamping and processing, the steel sleeve 100 will have rounded edges due to the clamping of the clamping jaws 11 and the turning action of the lathe, which will affect the subsequent use of the steel sleeve 100 and the overall life of the injection molding machine. It is worth mentioning that the roundness is not only caused by the clamping action of the clamping jaws 11. Since the material of the steel sleeve 100 itself has a certain elasticity, the clamped part will recover its deformation after the clamping jaws 11 are released. In addition, the steel sleeve 100 is deformed during clamping, causing the position of the turning tool relative to the steel sleeve 100 to change radially (the clamped part has a smaller turning amount due to deformation, and the unclamped part has a larger turning amount), which leads to the appearance of rounded edges. After the steel sleeve 100 recovers a certain deformation, this roundness will not recover.

[0065] In order to reduce the roundness of the steel sleeve 100, the inventor's first idea is to change the processing technology and process the steel sleeve 100 using a cylindrical grinder to reduce the possibility of roundness. However, the processing speed of the cylindrical grinder is slow and cannot meet the needs of large-scale processing. In addition, the straightness of the axis is also poor. The main reason is that the cylindrical grinder relies on the inner diameter of the steel sleeve 100 for positioning. The inner diameter has not been finely ground, and the positioning itself is not accurate enough, resulting in poor precision of the formed steel sleeve 100 and low processing efficiency.

[0066] The traditional method of improving the roundness of the centerless grinder is as follows: Figure 5 and Figure 6 As shown, Figure 5It is shown that when the height of the bracket 400 is low, the center heights of the steel sleeve 100, the guide wheel 200 and the grinding wheel 300 are basically the same, and one end of the relatively raised rounded steel sleeve 100 contacts the guide wheel 200, while the relatively depressed part contacts the grinding wheel 300, so the relatively depressed part is further ground off; and the steel sleeve 100 is further rotated 180° by the guide wheel 200, and the relatively depressed part contacts the grinding wheel 300. Due to the characteristics of the centerless grinder, the steel sleeve 100 will move toward the guide wheel 200, so that the grinding wheel 300 cannot be processed to the relatively raised part of the rounded part, so that the rounded part of the steel sleeve 100 cannot be repaired. Figure 6 As shown, by increasing the height of the bracket 400, the guide wheel 200 and the grinding wheel 300 can simultaneously resist the relative protrusions of the steel sleeve 100, thereby utilizing the inherent characteristics of the centerless grinder to repair its edge roundness. However, this method will cause the steel sleeve 100 to increase in ellipse, and is not conducive to the production of high-precision steel sleeves 100.

[0067] Therefore, the inventors have developed a new processing method, adding S41 to step S4: one clamping, and finishing turning the steel sleeve 100 to a length of 1 / 2 of the total length of the steel sleeve 100, and completing 1 / 2 of the grooving process (for example, if four grooves need to be cut, complete two of them first); S42: secondary clamping, turning the steel sleeve 100 for clamping, and making the clamping jaws 11 of the two clampings offset by 180° relative to the axial angle of the steel sleeve 100, and completing the remaining finishing and grooving processes.

[0068] This processing method utilizes the clamping force of the three-jaw chuck 1 and the influence of the turning action to make the front and rear sides of the steel sleeve 100 present a centrally symmetrical triangular prism, such as Figure 7 As shown in the figure (for the sake of clarity, the annular groove 102 and the axial groove 103 on the steel sleeve 100 are omitted, and the degree of the roundness caused by processing and clamping is magnified), the steel sleeve 100 can be repaired in the subsequent processing of the centerless grinder by the centerless grinder, thereby realizing the production of a steel sleeve 100 with higher precision. When the guide wheel 200 contacts the relatively concave part of the A side 105 of the steel sleeve 100, the relatively convex part on the B side 106 of the steel sleeve 100 also contacts the guide wheel 200, thereby correcting the displacement of the steel sleeve 100 caused by the influence of the roundness during the processing, so that the centerless grinder can repair the roundness during the processing, thereby producing a steel sleeve 100 with higher precision.

[0069] It is worth mentioning that although the four-point chuck can also be used to repair the roundness of the edges in the subsequent centerless grinder, the four-point chuck has poor centering ability, complicated clamping process, poor practicality, and inconvenient use. It is not suitable for conventional large-scale production. In addition, the processing process is slow and cannot be connected to the subsequent automatic clamping and automatic production system, resulting in the inability to reduce the processing cost.

[0070] In order to form a steel sleeve 100 with a centrally symmetrical triangle on the front and rear sides, the inventor further developed a clamping tool, such as Figures 8 to 25 As shown, a clamping tool for a steel sleeve 100 of an injection molding machine is installed at the front end of a lathe spindle. The clamping tool comprises a three-jaw chuck 1 and a positioning assembly 2. The three-jaw chuck 1 is detachably installed at the front end of the lathe spindle. The three-jaw chuck 1 has a clamping jaw 11. The clamping jaw 11 is suitable for clamping the outer side of the steel sleeve 100. The steel sleeve 100 is suitable for being sleeved on the outer side of the positioning assembly 2. During a clamping operation, the three-jaw chuck 1 is suitable for clamping the front side of the steel sleeve 100. The positioning assembly 2 is suitable for being detachably fixed on the rear side of the steel sleeve 100. The positioning assembly 2 extends axially backward. A positioning portion 21 is formed, and the positioning portion 21 is suitable for indicating that the axial misalignment angle of the virtual triangle formed by the steel sleeve 100 and the clamping jaws 11 of the three-jaw chuck 1 during the first clamping is α; during the second clamping, the positioning component 2 is kept detachably fixed to the inside of the rear side of the steel sleeve 100 and the steel sleeve 100 is turned, and the three-jaw chuck 1 is suitable for clamping the outside of the rear side of the steel sleeve 100, and the positioning portion 21 is suitable for being detachably fixed to the front side of the three-jaw chuck 1, and limiting the axial misalignment angle of the virtual triangle formed by the steel sleeve 100 and the clamping jaws 11 to α+180°.

[0071] This clamping tool has a positioning assembly 2 and a positioning portion 21. During a clamping operation, the positioning assembly 2 is fixed to the rear side of the steel sleeve 100 (i.e., the A side 105 of the steel sleeve 100), and the positioning portion 21 is used to indicate that the virtual triangle formed by the steel sleeve 100 and the clamping jaw 11 is misaligned by an angle α along the axial direction (in this specific embodiment, as shown in FIG. Figure 8 As shown, during the first clamping, the virtual triangle formed by the positioning portion 21 and the clamping jaws 11 has an axial misalignment angle of 0°); during the second clamping, the positioning component 2 is kept detachably fixed inside the rear side of the steel sleeve 100 (i.e., the A side 105) and the steel sleeve 100 is turned so that the front side of the steel sleeve 100 (i.e., the B side 106) faces outward, and the three-jaw chuck 1 is suitable for clamping the outside of the rear side of the steel sleeve 100 (i.e., the A side 105). Since the positioning portion 21 is detachably connected to the three-jaw chuck 1, the positioning portion 21 can be used to achieve an axial misalignment angle of α+180° (180° in this specific embodiment) of the virtual triangle formed by the steel sleeve 100 and the clamping jaws 11.

[0072] In this specific embodiment, since the virtual triangle formed by the positioning portion 21 and the clamping jaw 11 is axially displaced at an angle of 0° during one clamping, the positioning assembly 2 is fixedly connected to the steel sleeve 100 by a detachable method such as magnetic attraction. After the steel sleeve 100 is turned so that the B side 106 faces outward, the positioning portion 21 is connected to the three-jaw chuck 1 by a detachable method such as magnetic attraction, thereby achieving an axial dislocation angle of 180° between the virtual triangle formed by the positioning portion 21 and the clamping jaw 11. Therefore, during the two clamping processes, the two clamping positions of the virtual triangle formed by the clamping jaw 11 can be 180° axially symmetrical, thereby making the front and rear sides of the steel sleeve 100 present a symmetrical triangle, so as to facilitate the subsequent entry into the centerless grinder and the subsequent centerless grinding operation.

[0073] It is worth mentioning that there are many ways to use the positioning part 21 to indicate the axial misalignment angle of the virtual triangle formed by the steel sleeve 100 and the clamping jaws 11, such as using the shape of the positioning part 21 (such as an arrow shape) to make the direction of the arrow point to the direction of one of the clamping jaws 11, thereby ensuring that during the second clamping, the direction of the arrow can point to the 180° rotation direction of the clamping jaw 11. The detachable mounting method of the positioning component 2 and the steel sleeve 100 can be magnetic, and the detachable mounting method of the positioning part 21 and the three-jaw chuck 1 can also be magnetic, so that the positioning component 2 can control the angle of the virtual triangle formed by the positioning part 21 and the clamping jaws 11 when the positioning component 2 does not rotate relative to the steel sleeve 100, so as to achieve the virtual triangles formed by the clamping jaws 11 in the two clamping processes. The angle is 180° offset from each other in the axial direction.

[0074] The positioning part 21 on the positioning component 2 is used to indicate the axial misalignment angle between the deformed steel sleeve 100 and the clamping jaw 11 when the steel sleeve 100 is clamped once, and the positioning part 21 is used to achieve the axial misalignment angle of the steel sleeve 100 and the clamping jaw 11 to be α+180°, so that the steel sleeve 100 is easier to form a centrally symmetrical triangular prism with front and rear sides, the processing speed is faster, the installation is easier, and the operation difficulty is lower.

[0075] In addition, although the front and rear sides of the steel sleeve 100 can be made triangular in shape through reverse clamping, it is difficult to ensure that the triangular edges on the front and rear sides are centrally symmetrical triangles due to the lack of a positioning device. If the axial misalignment angle of the triangular edges on the front and rear sides is small, it is still impossible to use a centerless grinder to achieve the effect of repairing the roundness of the edges, resulting in poor repetition accuracy of the formed steel sleeve 100, and uneven force on the same moving template (four steel sleeves 100), so the purpose of improving the roundness of the edges of the steel sleeve 100 cannot be achieved.

[0076] Further preferably, Fig.10 and Fig.11As shown, the clamping tool also includes an auxiliary component 3, and the steel sleeve 100 is sleeved on the outside of the auxiliary component 3. During one clamping, the rear end of the auxiliary component 3 is suitable for being detachably mounted on the front end of the three-jaw chuck 1, and the front end of the auxiliary component 3 is detachably connected to the inside of the rear side of the steel sleeve 100. The auxiliary component 3 is suitable for controlling the axial misalignment angle of the virtual triangle composed of the steel sleeve 100 and the clamping jaw 11 during one clamping. The positioning component 2 is suitable for rough positioning through the auxiliary component 3, and determining the axial misalignment angle of the virtual triangle composed of the positioning component 2 and the clamping jaw 11.

[0077] When in use, the auxiliary component 3 is first detachably mounted on the front end of the three-jaw chuck 1, and the front end of the auxiliary component 3 and the interior of the rear side of the steel sleeve 100 are detachably connected to determine the axial misalignment angle between the virtual triangle formed by the clamping jaw 11 and the auxiliary component 3. At this time, a clamping is performed once, and the steel sleeve 100 is processed by a lathe; then the auxiliary component 3 can be used for rough positioning, so as to achieve relative positioning of the positioning component 2 and the auxiliary component 3, so as to determine the axial misalignment angle between the virtual triangle formed by the clamping jaw 11 and the positioning component 2; finally, a secondary clamping is performed, and the positioning component 2 is used to achieve that the two clamping positions of the virtual triangle formed by the clamping jaw 11 are 180° centrally symmetrical. There are many ways to achieve rough positioning, such as using magnetic attraction, bolts, etc., as long as the auxiliary component 3 and the positioning component 2 can be achieved without relative rotation in the axial direction.

[0078] The use of the auxiliary component 3 can more conveniently indicate the axial misalignment angle of the virtual triangle formed by the positioning component 2 relative to the clamping jaw 11. Since the auxiliary component 3 is fixed relative to the clamping jaw 11, by utilizing the rough positioning of the positioning component 2 and the auxiliary component 3, during one clamping, the axial misalignment angle α of the virtual triangle formed by the positioning component 2 relative to the clamping jaw 11 is fixed, and further after the clamping is reversed, the axial misalignment angle of the positioning component 2 relative to the virtual triangle formed by the clamping jaw 11 is α+180°.

[0079] Further preferably, Fig.10 and Fig.11 As shown, the positioning portion 21 is a polygonal column, the side edges are parallel to the axis and the number of the side edges is 3n (n is a positive integer and an odd number), an auxiliary positioning portion 31 is arranged on the outer side of the auxiliary component 3, the shape and size of the auxiliary positioning portion 31 are the same as those of the positioning portion 21, and the projection of the auxiliary positioning portion 31 and the positioning portion 21 on the cross section are centrally symmetrically arranged relative to the projection point of the axis on the cross section, and the front end of the three-jaw chuck 1 is provided with a mounting groove 12 matching the positioning portion 21, and the positioning component 2 and the auxiliary component 3 are suitable for being detachably connected to the front end of the three-jaw chuck 1 through the mounting groove 12.

[0080] In this specific embodiment, Fig.11A cross-sectional view is shown, in which the auxiliary component 3 is a triangular circle, wherein the solid triangular circle represents the positioning portion 21, and the dotted triangular circle represents the auxiliary positioning portion 31, and the projections of the auxiliary positioning portion 31 and the positioning portion 21 on the cross section are centrally symmetrically arranged relative to the projection point of the axis on the cross section (that is, the triangular circle is rotated 180° about the projection point of the axis on the cross section to coincide with the dotted triangular circle). A mounting groove 12 matching the positioning portion 21 is provided. During the first clamping, the auxiliary positioning portion 31 is installed in the mounting groove 12. Since the auxiliary positioning portion 31 and the positioning portion 21 are of the same size and shape and are axially offset by 180° (that is, the projections of the auxiliary positioning portion 31 and the positioning portion 21 on the cross section are centrally symmetrical with respect to the projection point of the axis on the cross section), when the second clamping is performed, the positioning portion 21 is still kept installed in the mounting groove 12. The clamping position of the steel sleeve 100 can be axially offset by 180° during the two clamping processes, so that the front and rear sides of the steel sleeve 100 are triangular prisms, and it is ensured that the prisms on the front and rear sides are axially offset by 180°.

[0081] The positioning portion 21 and the auxiliary positioning portion 31 are in the shape of a polygonal column, and the number of side edges is 3n (n is a positive integer and an odd number) in order to maintain the convenience of clamping. Since the three-jaw chuck 1 has three jaws 11, in order to reduce the difficulty of installation and positioning after U-turn clamping, the number of side edges is set to 3n (n is a positive integer and an odd number). This can ensure that even if the steel sleeve 100 is rotated less than 180°, the virtual triangle formed at the clamping position can be symmetrically arranged at 180° during the two clamping processes (taking the triangular edge circle as an example, rotating 60° after U-turn clamping can also ensure that the virtual triangle formed at the clamping position is symmetrically arranged at 180° during the two clamping processes). In addition, if n is an even number, the positioning portion 21 itself will be a centrally symmetrical figure, and it will be difficult to achieve the positioning effect after U-turn clamping.

[0082] Further preferably, Fig.12 and Fig.13 As shown, the positioning portion 21 is in the shape of a triangular prism, the cross-sectional shape of the mounting groove 12 is a triangle matching the positioning portion 21, and the virtual triangle formed with the clamping jaw 11 in the clamping state is axially offset by 180°. When the positioning portion 21 or the auxiliary positioning portion 31 is installed in the mounting groove 12, there is a gap between the groove wall of the mounting groove 12 and the outer wall of the positioning portion 21 or the auxiliary positioning portion 31.

[0083] It is worth mentioning that due to the combined effect of the three-jaw chuck 1 and turning, after one clamping and processing is completed, the jaws 11 are released, and the front part of the steel sleeve 100, that is, the A side 105, presents a triangular rounded shape. Although the B side 106 is clamped by the three-jaw chuck 1, it will also be deformed to a certain extent, but the steel sleeve 100 itself has elasticity, and this deformation will recover after the jaws 11 are released. However, since the steel sleeve 100 will affect the shape of the distal end (that is, the shape of the A side 105) during one clamping, coupled with the effect of turning, the distal end where the A side 105 is located presents an irreversible rounded shape. Similarly, after turning around and clamping, the proximal end where the B side 106 is located also presents an irreversible rounded shape.

[0084] Since the auxiliary positioning portion 31 and the positioning portion 21 are detachably mounted in the mounting groove 12 and detachably mounted on the front and rear sides of the steel sleeve 100, and the three-jaw chuck 1 itself also has positioning and centering functions, in order to avoid excessive positioning and causing unnecessary deformation of the steel sleeve 100, a gap d can be provided between the mounting groove 12 and the auxiliary positioning portion 31 or the positioning portion 21, such as Fig.13 As shown, at this time, although the virtual triangle formed by the clamping jaws 11 during the two clamping processes is not completely centrally symmetrical in the axial direction, this deviation can still be repaired using a centerless grinder.

[0085] Further preferably, Figures 14 to 17 As shown, an auxiliary limiting portion 32 is radially arranged outwardly on the auxiliary component 3, the auxiliary limiting portion 32 is made of elastic material, the outer wall of the auxiliary limiting portion 32 is suitable for contacting the inner wall of the mounting hole 104 on the steel sleeve 100, and the auxiliary component 3 is suitable for being detachably connected with the steel sleeve 100 through the auxiliary limiting portion 32; the positioning component 2 includes a connecting rod 23 and a limiting portion 22, the connecting rod 23 extends along the axial direction of the positioning component 2, and a triangular positioning pin 231 is arranged at the rear end of the connecting rod 23, and a positioning hole 3 matching the positioning pin 231 is arranged at the front end of the auxiliary component 3 5. The connecting rod 23 is detachably fixed to the front end of the auxiliary component 3 through the positioning pin 231 and the positioning hole 35. The front end of the connecting rod 23 is fixed on the positioning component 2. The connecting rod 23 is suitable for roughly positioning the relative positions of the positioning component 2 and the auxiliary component 3 along the axial direction. The limiting portion 22 is radially arranged outwardly on the outer side of the positioning component 2. The limiting portion 22 is made of elastic material. The outer wall of the limiting portion 22 is suitable for contacting the inner wall of the mounting hole 104 on the steel sleeve 100 and controlling the rotation angle of the positioning component 2 and the steel sleeve 100. The positioning portion 21 is arranged on the front side of the limiting portion 22.

[0086] like Figures 14 to 17As shown, an embodiment of rough positioning is shown. The positioning component 2 and the auxiliary component 3 are positioned at an axial rotation angle through the connecting rod 23, the positioning pin 231 and the positioning hole 35. Since the positioning pin 231 is a triangle, it can ensure that the auxiliary positioning part 31 and the positioning part 21 are axially offset by 180°. And the positioning component 2 and the auxiliary component 3 are detachably connected relative to the steel sleeve 100 by using the limiting part 22 and the auxiliary limiting part 32. When in use, the auxiliary component 3 is first fixed in the installation groove 12 and then fixed by the connecting rod 23. The positioning component 2 and the auxiliary component 3 are fixed relative to the steel sleeve 100 by using the limiting part 22 and the auxiliary limiting part 32, so that the virtual triangle formed by the clamping jaws 11 is axially symmetrically arranged.

[0087] Further preferably, another embodiment of coarse positioning is as follows: Figures 18 to 20 As shown, the auxiliary component 3 is provided with a plurality of auxiliary limiting portions 32 protruding radially outward, the auxiliary limiting portions 32 are made of elastic material, and are suitable for invading the lubrication holes 101 circumferentially arranged on the rear side of the steel sleeve 100 and limiting the relative rotation between the steel sleeve 100 and the auxiliary component 3; the positioning component 2 is provided with a plurality of limiting portions 22 protruding radially outward, the limiting portions 22 are made of elastic material, and are suitable for invading the lubrication holes 101 circumferentially arranged on the front side of the steel sleeve 100 and limiting the relative rotation between the steel sleeve 100 and the positioning component 2.

[0088] The limiting portion 22 and the auxiliary limiting portion 32 are provided on the positioning component 2 and the auxiliary component 3 to protrude radially outward, and the limiting portion 22 and the auxiliary limiting portion 32 are made to intrude into the lubrication hole 101, so as to realize the detachable connection between the positioning component 2 and the auxiliary component 3 relative to the steel sleeve 100, and by arranging the circumferentially distributed positions of the lubrication holes 101, the relative misalignment angle of the positioning component 2 and the auxiliary component 3 in the axial direction is controlled, so as to realize the rough positioning effect, and at the same time realize the detachable connection effect, and the positioning component 2 can be rotated to realize the rotation of the limiting portion 22, and the rotation angle of the limiting portion 22 relative to the steel sleeve 100 is adjusted, so as to control the relative rotation angle of the auxiliary component 3 and the positioning component 2.

[0089] Further preferably, Figure 22 to Figure 25As shown, the positioning assembly 2 includes a connecting column 24, and the steel sleeve 100 is sleeved on the outside of the connecting column 24. The connecting column 24 extends axially and forms a deformable bowl 25. The bottom of the deformable bowl 25 is connected to the connecting column 24. The outer bowl wall 252 of the deformable bowl 25 is projected as a concave curve in the longitudinal section. A plurality of limiting portions 22 are radially protruding outward on the outer wall of the bowl mouth of the deformable bowl 25. The limiting portions 22 are circumferentially arranged on the outer wall of the deformable bowl 25. During one clamping, the deformable bowl 25 and the connecting column 24 successively penetrate into the mounting hole 104 of the steel sleeve 100 axially backward. At this time, the connecting column 24 continues to be driven axially backward to deform the deformable bowl 25, and the limiting portions 22 and the steel sleeve 100 enter a locked state.

[0090] Through the combined effect of the deformable bowl 25 and the limiting portion 22, the detachable connection between the positioning component 2 and the steel sleeve 100 and the rough positioning with the auxiliary component 3 are better realized. Since the limiting portion 22 is made of elastic material, in order to facilitate the adjustment of the axial misalignment angle between the positioning component 2 and the steel sleeve 100, the height of the limiting portion 22 cannot be too high. However, controlling the height of the limiting portion 22 facilitates rotation, and the relative fixation of the positioning component 2 and the steel sleeve 100 after the rough positioning is completed cannot be achieved. The deformable bowl 25 is used and the projection of the outer bowl wall 252 on the longitudinal section is a concave curve such as Fig.23 As shown, after the rough positioning is completed, that is, the relative angle between the positioning assembly 2 and the steel sleeve 100 in the axial direction is determined, the connecting column 24 can be further driven from front to back to deform the deformation bowl 25 as shown in FIG. Fig.25 As shown, the material of the outer bowl wall 252 of the deformable bowl 25 is displaced in the direction of the dotted arrow, so that the contact area and contact force between the deformable bowl 25 and the steel sleeve 100 are increased, thereby achieving relative locking between the steel sleeve 100 and the positioning assembly 2, and entering a locked state. In addition, a locking portion 211 can be formed on the positioning portion 21 to expand radially outward to determine the maximum movement distance of the positioning assembly 2 in the axial direction.

[0091] Further preferably, Fig.19 As shown, the auxiliary component 3 includes an auxiliary connecting column 33, and the steel sleeve 100 is sleeved on the outside of the auxiliary connecting column 33. The auxiliary connecting column 33 extends axially and forms an auxiliary deformation bowl 34. The bottom of the auxiliary deformation bowl 34 is connected to the auxiliary connecting column 33. A plurality of auxiliary limiting portions 32 are radially protruding outward on the outer wall of the bowl mouth of the auxiliary deformation bowl 34. The auxiliary limiting portions 32 are circumferentially arranged on the outer wall of the auxiliary deformation bowl 34. During one clamping, the auxiliary connecting column 33 and the auxiliary deformation bowl 34 successively invade the mounting hole 104 of the steel sleeve 100 axially forward. At this time, the auxiliary connecting column 33 continues to be driven axially forward to deform the auxiliary deformation bowl 34, and the auxiliary limiting portions 32 and the steel sleeve 100 enter a locked state.

[0092] The auxiliary deformation bowl 34 and the auxiliary connection column 33 are provided on the auxiliary component 3 to facilitate the detachable fixing of the auxiliary component 3 and the steel sleeve 100, so as to achieve a relatively fixed connection between the auxiliary component 3 and the steel sleeve 100 during one clamping.

[0093] Further preferably, Figures 19 to 21 As shown, the bowl mouths of the deformable bowl 25 and the auxiliary deformable bowl 34 protrude radially outward and are circumferentially surrounded by a bearing portion 251 and an auxiliary bearing portion 341, and a limiting portion 22 and an auxiliary limiting portion 32 are radially protruded on the bearing portion 251 and the auxiliary bearing portion 341, respectively. The bearing portion 251 and the auxiliary bearing portion 341 are made of elastic material, and the outer walls of the bearing portion 251 and the auxiliary bearing portion 341 are suitable for contacting the inner wall of the mounting hole 104 of the steel sleeve 100; the connecting column 24 and the auxiliary connecting column 33 are made of rigid material, and there is a gap between the outer walls of the connecting column 24 and the auxiliary connecting column 33 and the steel sleeve 100.

[0094] The bearing portion 251 and the auxiliary bearing portion 341 are provided to increase the contact area between the deformable bowl 25 and the auxiliary deformable bowl 34 and the steel sleeve 100 when in use, and the connecting column 24 and the auxiliary connecting column 33 are provided for rigidity to increase the rigidity of the auxiliary component 3 and the positioning component 2, and to create a gap between them and the steel sleeve 100 to prevent them from excessively limiting the positioning component 2, the auxiliary component 3 and the steel sleeve 100.

[0095] A steel sleeve 100 for an injection molding machine made of the above clamping tooling, such as Figure 1 As shown, the lubrication holes 101 on the steel sleeve 100 are radially arranged and connected to the mounting holes 104 of the steel sleeve 100. The lubrication holes 101 are circumferentially arranged and axially arranged on the steel sleeve 100. The number of lubrication holes 101 arranged in the axial direction is 2x rows (x is a positive integer), and the number of lubrication holes 101 distributed circumferentially is 3y (y is a positive integer).

[0096] In this specific embodiment, the number of lubrication holes 101 arranged in the axial direction is 4 rows, the number of lubrication holes 101 distributed in the circumferential direction is 9, and the number of lubrication holes 101 arranged in the axial direction is set to 2x rows (x is a positive integer) in order to meet the requirement that the processing amount on both sides is basically the same during the grooving process, thereby ensuring that the prism sizes on both sides of the steel sleeve 100 are basically the same; the number of sliding holes 101 distributed in the circumferential direction is 3y (y is a positive integer), which is for more convenient rough positioning of the relative position between the positioning component 2 and the auxiliary component 3. Specifically, since the shape of the positioning portion 21 is a triangular prism, the auxiliary positioning portion 31 is symmetrically arranged relative to the projection center of the positioning portion 21 on the cross section, and each vertex can correspond to y lubrication holes 101, so as to more conveniently realize the correspondence between the lubrication hole 101 and the vertex, and more conveniently adopt visual inspection or machine vision to realize the auxiliary component 3 and the positioning component 2 to be 180° offset from each other in the axial direction.

[0097] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A clamping tool for a steel sleeve of an injection molding machine, mounted on the front end of a lathe spindle, characterized in that: The clamping tool comprises a three-jaw chuck and a positioning assembly, wherein the three-jaw chuck is detachably mounted on the front end of the lathe spindle, and the three-jaw chuck has a clamping jaw, wherein the clamping jaw is suitable for clamping the outer side of the steel sleeve, and the steel sleeve is suitable for being sleeved on the outer side of the positioning assembly; During the first clamping, the three-jaw chuck is suitable for clamping the front side of the steel sleeve, the positioning assembly is suitable for being detachably fixed to the rear side of the steel sleeve, the positioning assembly extends axially backward and is formed with a positioning portion, the positioning portion is suitable for indicating that the virtual triangle formed by the steel sleeve and the clamping jaws of the three-jaw chuck during the first clamping has an axial misalignment angle of α; during the second clamping, the positioning assembly is kept detachably fixed to the inside of the rear side of the steel sleeve and the steel sleeve is turned, and the three-jaw chuck is suitable for clamping the outside of the rear side of the steel sleeve, the positioning portion is suitable for being detachably fixed to the front side of the three-jaw chuck, and limiting the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws to α+180°, The clamping fixture also includes an auxiliary component, the steel sleeve is arranged on the outside of the auxiliary component, and during a clamping operation, the rear end of the auxiliary component is suitable for being detachably mounted on the front end of the three-jaw chuck, and the front end of the auxiliary component is detachably connected to the inside of the rear side of the steel sleeve, and the auxiliary component is suitable for controlling the axial misalignment angle of the virtual triangle formed by the steel sleeve and the clamping jaws during a clamping operation, and the positioning component is suitable for performing rough positioning through the auxiliary component and determining the axial misalignment angle of the virtual triangle formed by the positioning component and the clamping jaws, The positioning portion is a polygonal column, the side edges are parallel to the axis and the number of side edges is 3n, n is a positive integer and an odd number, an auxiliary positioning portion is arranged on the outer side of the auxiliary component, the shape and size of the auxiliary positioning portion are the same as those of the positioning portion, and the auxiliary positioning portion and the projection of the positioning portion on the cross section are centrally symmetrically arranged relative to the projection point of the axis on the cross section, the front end of the three-jaw chuck is provided with a mounting groove matching the positioning portion, and the positioning component and the auxiliary component are suitable for being detachably connected to the front end of the three-jaw chuck through the mounting groove, The positioning portion is in the shape of a triangular prism, the cross-sectional shape of the mounting groove is a triangle matching the positioning portion, and is axially offset by 180° with a virtual triangle formed by the clamping jaws in the clamping state. When the positioning portion or the auxiliary positioning portion is installed in the mounting groove, there is a gap between the groove wall of the mounting groove and the outer wall of the positioning portion or the auxiliary positioning portion.

2. A clamping tool for a steel sleeve of an injection molding machine as claimed in claim 1, characterized in that: An auxiliary limiting portion is radially arranged outwardly on the auxiliary component, the auxiliary limiting portion is made of elastic material, the outer wall of the auxiliary limiting portion is suitable for contacting the inner wall of the mounting hole on the steel sleeve, and the auxiliary component is suitable for being detachably connected to the steel sleeve through the auxiliary limiting portion; the positioning component comprises a connecting rod and a limiting portion, the connecting rod extends along the axial direction of the positioning component, and a triangular positioning pin is arranged at the rear end of the connecting rod, a positioning hole matching the positioning pin is arranged at the front end of the auxiliary component, the connecting rod is detachably fixed to the front end of the auxiliary component through the positioning pin and the positioning hole, the front end of the connecting rod is fixed on the positioning component, the connecting rod is suitable for roughly positioning the relative positions of the positioning component and the auxiliary component along the axial direction, the limiting portion is radially arranged outwardly on the outside of the positioning component, the limiting portion is made of elastic material, the outer wall of the limiting portion is suitable for contacting the inner wall of the mounting hole on the steel sleeve, and controlling the rotation angle of the positioning component and the steel sleeve, and the positioning portion is arranged on the front side of the limiting portion.

3. A clamping tool for a steel sleeve of an injection molding machine as claimed in claim 1, characterized in that: The auxiliary component is provided with a plurality of auxiliary limiting parts protruding radially outward, the auxiliary limiting parts are made of elastic material, and the auxiliary limiting parts are suitable for invading the lubrication holes circumferentially arranged on the rear side of the steel sleeve and limiting the relative rotation between the steel sleeve and the auxiliary component; the positioning component is provided with a plurality of limiting parts protruding radially outward, the limiting parts are made of elastic material, and the limiting parts are suitable for invading the lubrication holes circumferentially arranged on the front side of the steel sleeve and limiting the relative rotation between the steel sleeve and the positioning component.

4. A clamping tool for a steel sleeve of an injection molding machine as claimed in claim 3, characterized in that: The positioning assembly includes a connecting column, the steel sleeve is arranged on the outside of the connecting column, the connecting column extends axially and forms a deformation bowl, the bottom of the deformation bowl is connected to the connecting column, the outer bowl wall of the deformation bowl is projected as a concave curve in the longitudinal section, and a plurality of limiting parts are provided on the outer wall of the bowl mouth of the deformation bowl protruding radially outward, and the limiting parts are circumferentially arranged on the outer wall of the deformation bowl. During one clamping, the deformation bowl and the connecting column are successively axially backward intruded into the mounting hole of the steel sleeve, and at this time, the connecting column is continued to be driven axially backward to deform the deformation bowl, and the limiting part and the steel sleeve are put into a locked state.

5. A clamping tool for a steel sleeve of an injection molding machine as claimed in claim 4, characterized in that: The auxiliary component includes an auxiliary connecting column, the steel sleeve is arranged on the outside of the auxiliary connecting column, the auxiliary connecting column extends axially and forms an auxiliary deformation bowl, the bottom of the auxiliary deformation bowl is connected to the auxiliary connecting column, and a plurality of auxiliary limiting parts are radially protruding outward on the outer wall of the bowl mouth of the auxiliary deformation bowl, and the auxiliary limiting parts are circumferentially arranged on the outer wall of the auxiliary deformation bowl. During one clamping, the auxiliary connecting column and the auxiliary deformation bowl are sequentially axially invaded into the mounting hole of the steel sleeve. At this time, the auxiliary connecting column is continued to be driven axially forward to deform the auxiliary deformation bowl, and the auxiliary limiting part and the steel sleeve are put into a locked state.

6. A clamping tool for a steel sleeve of an injection molding machine as claimed in claim 5, characterized in that: The bowl mouths of the deformable bowl and the auxiliary deformable bowl respectively protrude radially outward and are circumferentially surrounded by a bearing portion and an auxiliary bearing portion, the bearing portion and the auxiliary bearing portion are respectively radially protrudingly provided with the limiting portion and the auxiliary limiting portion, the bearing portion and the auxiliary bearing portion are made of elastic material, and the outer walls of the bearing portion and the auxiliary bearing portion are suitable for contacting the inner wall of the mounting hole of the steel sleeve; the connecting column and the auxiliary connecting column are made of rigid material, and there is a gap between the outer walls of the connecting column and the auxiliary connecting column and the steel sleeve.

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