Hollow shaft positive extrusion die

Abstract

The hollow shaft positive extrusion die comprises an upper die and a lower die, the upper die comprises an upper die base, an upper die sleeve, an upper die sleeve, an outer punch, an inner punch and an elastic device, one end of the outer punch is limited inside the inner cavity of the die sleeve, the outer punch can move back and forth in the inner cavity of the die sleeve, one end of the inner punch is limited inside the inner cavity of the outer punch, the inner punch can move back and forth in the inner cavity of the outer punch, the other end of the inner punch extends out of the inner cavity of the outer punch, the elastic device is arranged between the bottom of the outer punch and the inner punch, the initial state of the elastic device is a compression state, and the elastic device always gives the inner punch an outward thrust. The application solves the problems that the positive extrusion is changed into punching when the workpiece cavity is first extruded, and the workpiece cavity is deformed when the end face of the workpiece is first extruded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision forging forming, in particular to a hollow shaft positive extrusion die. BACKGROUND

[0002] The hollow shaft is an important part in the motor, and the product has high requirements and large market demand. In the traditional manufacturing, the blank making, rotary forging and machining are generally used for processing, but the process has long processing time, many flow times and large material consumption. Therefore, the convenient way of forging becomes the first choice for reducing the manufacturing cost, and the deep cavity positive extrusion die in the previous forging is a rigid structure with a punch, if the inner cavity is extruded first, the positive extrusion becomes punching, and if the inner cavity of the workpiece is deformed first, the subsequent cavity is difficult to process, so that the normal forging is difficult to complete.

[0003] Therefore, it is necessary to provide a new technical scheme. SUMMARY

[0004] In order to solve the technical problems in the prior art, the present application discloses a hollow shaft positive extrusion die, and the specific technical scheme is as follows:

[0005] The present application provides a hollow shaft positive extrusion die, which comprises an upper die and a lower die, wherein the upper die comprises:

[0006] An upper die seat;

[0007] An upper die sleeve, one end of which is fixed to the upper die seat, and the upper die sleeve is provided with an upper die sleeve inner cavity;

[0008] An upper die sleeve sleeve, which is arranged at the other end of the upper die sleeve, and the end of the upper die sleeve sleeve extends inwardly to form a sleeve step with the upper die sleeve inner cavity;

[0009] An outer punch, one end of which is arranged in the die sleeve inner cavity, and the outer punch can move back and forth in the upper die sleeve inner cavity, the bottom of the outer punch is provided with a first step which protrudes outward, the first step can be engaged with the sleeve step, the sleeve step limits the end of the outer punch inside the upper die sleeve inner cavity, the outer punch is provided with an outer punch inner cavity, and the upper part of the outer punch inner cavity is provided with an outer punch step which protrudes inwardly;

[0010] An inner punch, one end of which is arranged inside the outer punch inner cavity, and the inner punch can move back and forth in the outer punch inner cavity, the bottom of the inner punch is provided with a second step which protrudes outward, the second step can be engaged with the outer punch step, the outer punch step limits the end of the inner punch inside the outer punch inner cavity, and the other end of the inner punch extends out of the outer punch inner cavity; and

[0011] An elastic device is arranged inside the outer punch inner cavity, and the elastic device is arranged between the bottom of the outer punch inner cavity and the inner punch, and the initial state of the elastic device is a compressed state, and the elastic device always provides an outward thrust to the inner punch.

[0012] Further, the other end of the upper die sleeve is provided with a thread matched with the upper die sleeve, and the upper die sleeve is fixed with the upper die sleeve through thread connection.

[0013] Further, the elastic device is a spring, and the normal length of the spring is greater than the depth of the outer punch inner cavity.

[0014] Further, the lower die comprises:

[0015] A lower die seat;

[0016] A lower die sleeve is fixed at one end of the lower die seat, and the lower die sleeve is provided with a lower die sleeve inner cavity;

[0017] A first die is arranged in the lower die sleeve inner cavity, and the bottom of the first die is provided with a concave structure recessed upward;

[0018] A second die is arranged in the lower die sleeve inner cavity, and the second die is arranged below the first die, and the top of the second die is provided with a convex structure protruding outward matched with the concave structure, and the second die and the first die are tightly connected through the convex structure and the concave structure; and

[0019] A lower die pressing plate is arranged above the first die, and the lower die pressing plate is pressed on the top of the first die to fix the first die and the second die in the lower die sleeve inner cavity.

[0020] Further, the first die is centrally provided with a first die inner cavity, the first die inner cavity is provided with a ligament structure, the ligament structure is located at the top end of the small diameter step of the first die inner cavity, the shape of the ligament structure is the same as that of the product, the length of the ligament structure is 3mm, and the diameter of the first die inner cavity below the ligament structure is 0.5mm larger than the diameter of the ligament structure.

[0021] Further, the second die is centrally provided with a second die inner cavity, and the upper part of the second die inner cavity is provided with a righting ligament structure, the diameter of the righting ligament structure is greater than that of the ligament structure, the position of the righting ligament structure is 1-1.5 times the length of the ligament structure diameter away from the ligament structure, and the diameter of the righting ligament structure is 0.1mm greater than that of the ligament structure.

[0022] Further, the top edge of the first die cavity is provided with a mold entry angle, the angle of the mold entry angle is 5°, and the segment length of the mold entry angle is 10mm.

[0023] The present application has the following advantages:

[0024] 1. The hollow shaft positive extrusion die provided by the present application is simple in structure, ingenious in design, and convenient for production and large-scale promotion and use.

[0025] 2. The hollow shaft positive extrusion die provided by the present application solves the problems that the positive extrusion is easily changed into punching when the workpiece cavity is first extruded, and the workpiece cavity is easily deformed when the workpiece end face is first extruded.

[0026] 3. The hollow shaft positive extrusion die provided by the present application uses a spring to make the inner punch contact but not extrude the workpiece when the inner punch enters the workpiece, and the inner punch is always in the workpiece cavity under the pressure of the spring to prevent the workpiece cavity from deforming, thereby solving the problem of positive extrusion forging.

[0027] 4. The hollow shaft positive extrusion die provided by the present application only has the ligament structure in contact with the product during extrusion, the ligament structure helps to reduce the contact area of the workpiece and the die, reduce the friction during extrusion, and is more conducive to pressurization.

[0028] 5. The hollow shaft positive extrusion die provided by the present application helps to improve the coaxiality of the workpiece through the righting ligament structure, and when the length of the extruded product is relatively long, the righting ligament structure can limit the bending size, thereby improving the coaxiality of the product.

[0029] 6. The hollow shaft positive extrusion die provided by the present application adopts the boss structure and the recess structure to ensure the coaxiality of the die cavity and that the first die and the second die will not be separated during forging.

[0030] Additional aspects and advantages of the present application will be made partially clear in the following description, partially become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0032] Figure 1 is a structure diagram of the hollow shaft positive extrusion die provided by the present application.

[0033] Figure 2 is Figure 1Structure diagram of the inner punch, the outer punch and the spring.

[0034] Figure 3 is Figure 1 Structure diagram of the first die.

[0035] Figure 4 is Figure 1 Structure diagram of the second die.

[0036] Figure 5 is Figure 3 Structure diagram of the entry angle. DETAILED DESCRIPTION

[0037] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0038] In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0039] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] The present application discloses a hollow shaft positive extrusion die, referring to Figures 1 to 5 , comprising an upper die 1 and a lower die 2, the upper die 1 comprising an upper die seat 11, an upper die sleeve 12, an upper die sleeve 13, an outer punch 14, an inner punch 15 and an elastic device 16. The lower die 2 comprises a lower die seat 21, a lower die sleeve 22, a first die 23, a second die 24 and a lower die pressing plate 25.

[0041] One end of the upper die sleeve 12 is fixed to the upper die seat 11, and the upper die sleeve 12 is provided with an upper die sleeve inner cavity.

[0042] An upper die sleeve 13 is arranged at the other end of the upper die sleeve 12, and the end of the upper die sleeve 13 extends inwardly to form a sleeve step in the inner cavity of the upper die sleeve.

[0043] An outer punch 14 is arranged at one end in the inner cavity of the upper die sleeve, and the outer punch 14 can move back and forth in the inner cavity of the upper die sleeve. The bottom of the outer punch 14 is provided with a first step that protrudes outwardly, and the first step can be engaged with the sleeve step. The sleeve step limits the end of the outer punch 14 inside the inner cavity of the upper die sleeve. The outer punch 14 is provided with an inner cavity, and the upper part of the inner cavity of the outer punch is provided with an inner punch step that protrudes inwardly.

[0044] An inner punch 15 is arranged at one end inside the inner cavity of the outer punch, and the inner punch 15 can move back and forth in the inner cavity of the outer punch. The bottom of the inner punch 15 is provided with a second step that protrudes outwardly, and the second step can be engaged with the outer punch step. The outer punch step limits the end of the inner punch 15 inside the inner cavity of the outer punch. The other end of the inner punch 15 extends out of the inner cavity of the outer punch.

[0045] A resilient device 16 is arranged inside the inner cavity of the outer punch, and the resilient device 16 is arranged between the bottom of the inner cavity of the outer punch and the inner punch 15. The initial state of the resilient device 16 is a compressed state, and the resilient device 16 always provides an outward pushing force to the inner punch 15.

[0046] In one embodiment, the other end of the upper die sleeve 12 is provided with a thread that matches the upper die sleeve 13, and the upper die sleeve 13 is fixed to the upper die sleeve 12 by thread connection.

[0047] In one embodiment, the resilient device 16 is a spring, and the normal length of the spring is greater than the depth of the inner cavity of the outer punch.

[0048] The lower die sleeve 22 is fixed at one end to the lower die seat 21, and the lower die sleeve 22 is provided with a lower die sleeve inner cavity.

[0049] A first die 23 is arranged in the lower die sleeve inner cavity, and the bottom of the first die 23 is provided with a concave step structure that protrudes upwardly. A second die 24 is arranged in the lower die sleeve inner cavity, and the second die 24 is arranged below the first die 23. The top of the second die 24 is provided with a convex step structure that protrudes outwardly and matches the concave step structure. The second die 24 and the first die 23 are tightly connected through the convex step structure and the concave step structure.

[0050] A lower die pressing plate 25 is arranged above the first die 23, and the lower die pressing plate 25 is pressed on the top of the first die 23 to fix the first die 23 and the second die 24 in the lower die sleeve inner cavity.

[0051] In one embodiment, the first die 23 is centrally provided with a first die inner cavity, and the first die inner cavity is provided with a ligament structure 231. The ligament structure 231 is located at the top end of the small-diameter step of the first die inner cavity, the shape of the ligament structure 231 is the same as that of the product, the length of the ligament structure 231 is 3 mm, and the diameter of the first die inner cavity below the ligament structure 231 is 0.5 mm larger than the diameter of the ligament structure 231.

[0052] In one embodiment, the second die 24 is centrally provided with a second die inner cavity, and the upper part of the second die inner cavity is provided with a righting ligament structure 241, and the diameter of the righting ligament structure 241 is larger than that of the ligament structure 231. The righting ligament structure 241 is located at a distance of 1-1.5 times the ligament structure diameter from the ligament structure 231, and the diameter of the righting ligament structure 241 is 0.1 mm larger than that of the ligament structure 231.

[0053] In one embodiment, the top edge of the first die inner cavity is provided with a mold entry angle 232, the angle of the mold entry angle 232 is 5°, and the segment length of the mold entry angle 232 is 10 mm.

[0054] The working principle of the present application is that the inner punch is compressed and shortened by the spring, so that the hollow shaft does not participate in the extrusion deformation during the positive extrusion, and can always remain in the workpiece, solving the problems that the positive extrusion is easily changed into punching when the workpiece cavity is first extruded, and the workpiece cavity is easily deformed when the workpiece end face is first extruded.

[0055] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application.

[0056] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications and variations to the above embodiments within the scope of the present application.

Claims

1. A hollow shaft positive extrusion die comprising an upper die and a lower die, characterized in that, The upper mold includes: Upper mold base; An upper mold sleeve, one end of which is fixed to the upper mold base, and the upper mold sleeve is provided with an inner cavity; An upper mold sleeve is disposed at the other end of the upper mold sleeve, and the end of the upper mold sleeve extends inward to form a sleeve step with the inner cavity of the upper mold sleeve; An outer punch, one end of which is disposed within the inner cavity of the upper mold sleeve, is movable back and forth within the inner cavity of the upper mold sleeve. The bottom of the outer punch is provided with an outwardly protruding first step, which can engage with the retaining sleeve step. The retaining sleeve step restricts one end of the outer punch within the inner cavity of the upper mold sleeve. The outer punch is provided with an outer punch inner cavity, and the upper part of the outer punch inner cavity is provided with an inwardly protruding outer punch step. An inner punch, one end of which is disposed inside the inner cavity of the outer punch, allows the inner punch to move back and forth within the inner cavity of the outer punch. The bottom of the inner punch has an outwardly protruding second step, which engages with the outer punch step. The outer punch step confines one end of the inner punch within the inner cavity of the outer punch, while the other end of the inner punch extends out of the inner cavity of the outer punch. An elastic device is disposed inside the inner cavity of the outer punch, and the elastic device is disposed between the bottom of the inner cavity of the outer punch and the inner punch. The initial state of the elastic device is a compressed state, and the elastic device always provides an outward thrust to the inner punch.

2. The hollow spindle positive extrusion die of claim 1, wherein, The upper mold sleeve has a threaded inner side, and the other end of the upper mold sleeve has a threaded outer side that matches the upper mold sleeve. The upper mold sleeve and the upper mold sleeve are fixed together by the threaded connection.

3. The hollow spindle positive extrusion die of claim 1, wherein, The elastic device is a spring, and the normal length of the spring is greater than the depth of the inner cavity of the outer punch.

4. The hollow spindle positive extrusion die of claim 1, wherein, The lower mold includes: Lower mold base; A lower mold sleeve, one end of which is fixed on the lower mold base, and the lower mold sleeve is provided with an inner cavity; The first die is disposed in the inner cavity of the lower die sleeve, and the bottom of the first die is provided with an upwardly recessed platform structure; The second die is disposed within the inner cavity of the lower die sleeve, and is located below the first die. The top of the second die has an outwardly protruding boss structure that matches the recessed platform structure. The second die and the first die are tightly connected via the boss structure and the recessed platform structure. A lower die plate is disposed above the first die cavity. The lower die plate presses against the top of the first die cavity, fixing the first die cavity and the second die cavity in the inner cavity of the lower die sleeve.

5. The hollow spindle positive extrusion die of claim 4, wherein, The first die has a central cavity, and a ligament structure is provided in the cavity. The ligament structure is located at the top of the small-diameter step of the cavity. The shape of the ligament structure is the same as that of the product, and the length of the ligament structure is 3mm. The diameter of the cavity below the ligament structure is 0.5mm larger than the diameter of the ligament structure.

6. A hollow spindle positive extrusion die according to claim 5, characterised in that The second concave die is centrally provided with a second concave die inner cavity, an upper portion of the second concave die inner cavity is provided with a righting ligament structure, a diameter of the righting ligament structure is greater than a diameter of the ligament structure, a position of the righting ligament structure is at a length of 1-1.5 times of the ligament structure diameter, and the diameter of the righting ligament structure is greater than the diameter of the ligament structure by 0.1 mm.

7. The hollow spindle positive extrusion die of claim 4 wherein, An edge of a top portion of the first concave die inner cavity is provided with a mold entry angle, an angle of the mold entry angle is 5°, and a segment length of the mold entry angle is 10 mm.

Images