Plastic processing mechanism for cylindrical workpiece with inner rib and thinning method

Abstract

The invention discloses a plastic processing mechanism for a cylindrical workpiece with an inner rib and a thinning method. The plastic processing mechanism for the cylindrical workpiece with the inner rib comprises a head seat, a push rod, a baffle plate, a die holder, an inner core shaft, a traction mechanism step oil cylinder, a tail seat and an outer die ring, a telescopic oil cylinder of a traction mechanism pulls the assembly to penetrate through a die hole of the outer die ring, and the stress state of the cylindrical workpiece with the inner rib in a gap between the outer wall of the inner core shaft and the inner wall of the outer die ring is three-way pressure stress; and the deformation defects of drawing cracks and the like caused by different axial tensile stresses on all parts of the cross section of the cylindrical workpiece with the inner rib in the drawing process of the conventional long rod mandrel are avoided. And meanwhile, under the action of pressure stress, the microdefects of looseness, shrinkage cavities and the like of the cylindrical part are eliminated, the fine grain strengthening effect is achieved, the wall thickness of the cylindrical part with the inner rib is effectively reduced under the conditions that the workpiece has the complex section characteristics of large rib and high wall thickness ratio and the diameter is large, and the machining precision, the yield and the mechanical property of the cylindrical part are improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal processing, and in particular to a plastic processing mechanism and a thinning method for a cylindrical workpiece with inner ribs. Background Art

[0002] Drawing is a metal processing method with the characteristics of high forming accuracy, good surface quality, high forming efficiency and the ability to improve workpiece strength. It is widely used in the production of rotationally symmetrical workpieces such as bars, wires, and tubes. However, for non-rotationally symmetrical cylindrical workpieces, especially cylindrical workpieces with internal ribs, it is difficult to effectively reduce the diameter and lengthen large cylindrical workpieces with internal ribs when drawing with a mandrel due to the uneven distribution of friction between the workpiece and the inner and outer dies in the circumferential direction, and cracks or even breakage caused by the difference in tensile deformation between the cylinder wall and the internal ribs. Therefore, it is necessary to propose a plastic processing mechanism and thinning method for cylindrical workpieces with internal ribs to solve the above problems. Summary of the invention

[0003] The object of the present invention is to provide a plastic processing mechanism and thinning method for a cylindrical workpiece with internal ribs, so as to solve the problem that the prior art is difficult to effectively realize the diameter reduction and lengthening processing of large cylindrical workpieces with internal ribs.

[0004] In the first aspect, the present invention provides a plastic processing mechanism for a cylindrical workpiece with internal ribs, comprising: a head seat, a push rod, a baffle, a die base, an inner core shaft, a traction mechanism stepped cylinder, a tail seat and an outer die ring; the head seat, the die base and the tail seat are arranged in parallel and spaced apart in sequence; the push rod is arranged on the head seat and can move in the horizontal direction, and an outer die ring is arranged in the die base; the traction mechanism stepped cylinder is arranged on the tail seat; the baffle is installed at the tail end of the inner core shaft, and the tail end of the inner core shaft is connected and fixed to the push rod; the traction mechanism stepped cylinder is connected to the head end of the inner core shaft; the internal cross-sectional geometry and size of the cylindrical workpiece are consistent with those of the inner core shaft, the cylindrical workpiece is assembled to the inner core shaft, and the tail end of the cylindrical workpiece contacts the baffle; the push rod is used to push the inner core shaft into the outer die ring, and the traction mechanism stepped cylinder is used to pull the inner core shaft and the cylindrical workpiece through the outer die ring.

[0005] Furthermore, the headstock, the die stock and the tailstock are connected and reinforced by frame support rods.

[0006] Furthermore, the push rod, the inner core shaft, the traction mechanism step cylinder and the outer mold ring are coaxial.

[0007] Furthermore, the surface of the inner core shaft is processed with grooves that are consistent with the geometric shape of the cylindrical workpiece ribs.

[0008] In a second aspect, the present invention provides a method for thinning a cylindrical workpiece with internal ribs, the method being implemented by the above-mentioned plastic processing mechanism for a cylindrical workpiece with internal ribs, and the method comprising the following steps:

[0009] Step 1: Install the baffle to the tail end of the inner core shaft, install the outer die ring into the die base, and extend the traction mechanism step cylinder to one side of the die base;

[0010] Step 2: transport the ribbed cylindrical workpiece to a heating furnace, wait for heating to a preset temperature and maintain it for a preset time;

[0011] Step three, lift the heated cylindrical workpiece and put it into the inner core shaft to form an assembly, connect the push rod with the tail end of the inner core shaft, and push the head end of the inner core shaft through the outer die ring through the push rod; connect the traction mechanism step cylinder with the head end of the inner core shaft, start the traction mechanism step cylinder and the push rod at the same time, and the traction mechanism step cylinder contracts to drive the assembly to pass through the die hole of the outer die ring, and compress and thin the wall thickness of the cylindrical workpiece under the extrusion of the inner wall of the outer die ring and the outer wall of the inner core shaft; wait for the baffle plate to move to one side of the die base, and the traction mechanism step cylinder and the push rod stop working, and complete the single-pass thinning deformation of the ribbed cylindrical workpiece;

[0012] Step 4: The step cylinder of the traction mechanism extends and the push rod returns to drive the assembly to exit the outer die ring, the push rod is disconnected from the inner core shaft, the assembly is taken out and the cylindrical workpiece is unloaded;

[0013] Step 5, replace the outer die ring with different apertures, repeat steps 1 to 4, and complete the wall thinning of the cylindrical workpiece with internal ribs.

[0014] The present invention has the following beneficial effects: the plastic processing mechanism and thinning method for a cylindrical workpiece with inner ribs of the present invention pulls the assembly through the outer die ring die hole through the telescopic oil cylinder of the traction mechanism, and the stress state of the cylindrical workpiece with inner ribs in the gap between the outer wall of the inner core shaft and the inner wall of the outer die ring is a three-dimensional compressive stress, which avoids the deformation defects such as drawing cracks caused by the different axial tensile stresses on the cross section of the cylindrical workpiece with inner ribs in the conventional long rod core shaft drawing process. At the same time, under the action of compressive stress, microscopic defects such as looseness and shrinkage of the cylinder are eliminated and a fine grain strengthening effect is achieved. Under the condition that the workpiece has a complex cross-sectional feature of large ribs and a high wall thickness ratio and a large diameter, the wall thickness of the cylindrical workpiece with inner ribs is effectively reduced, thereby improving the processing accuracy, yield rate and mechanical properties of the cylindrical workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 This is a schematic diagram of the working state of the present invention. Figure 1 ;

[0017] Figure 2 yes Figure 1 A cross-sectional view of

[0018] Figure 3 This is a schematic diagram of the working state of the present invention. Figure 2 ;

[0019] Figure 4 It is along Figure 2 Sectional view of AA in the middle;

[0020] Figure 5 It is a front view of the inner mandrel;

[0021] Figure 6 is a cross-sectional view of the inner core shaft;

[0022] Figure 7 It is a cross-sectional view of a cylindrical workpiece with internal ribs;

[0023] Illustration: 1-head seat; 2-push rod; 3-frame support rod; 4-baffle; 5-cylindrical workpiece; 6-die base; 7-inner core shaft; 8-traction mechanism ladder cylinder; 9-tail seat; 10-outer die ring. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present application belongs.

[0025] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0026] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for clarity, the thickness of the layers and regions is enlarged, and the same reference numerals are used to represent the same devices, so their description will be omitted.

[0027] See also Figures 1 to 7 An embodiment of the present invention provides a plastic processing mechanism for a cylindrical workpiece with internal ribs, including: a head seat 1, a push rod 2, a baffle 4, a die seat 6, an inner core shaft 7, a traction mechanism step cylinder 8, a tail seat 9 and an outer die ring 10.

[0028] Among them, the head seat 1, the die seat 6 and the tail seat 9 are arranged in parallel and fixed on the foundation, and the four corners between the head seat 1, the die seat 6 and the tail seat 9 are connected and reinforced by the frame support rod 3; the push rod 2 is arranged on the head seat 1 and can move in the horizontal direction, and the die seat 6 is provided with an outer die ring 10; the traction mechanism ladder cylinder 8 is arranged on the tail seat 9. The baffle 4 is installed at the tail end of the inner core shaft 7 by screws, and the baffle 4 is used to limit the axial movement of the cylindrical workpiece 5; the tail end of the inner core shaft 7 is connected and fixed with the push rod 2 by screws, and the push rod 2 is used to support the inner core shaft 7 and push the cylindrical workpiece 5 and one end of the inner core shaft 7 through the outer die ring 10, so as to facilitate the connection with the traction mechanism ladder cylinder 8. The traction mechanism ladder cylinder 8 is connected to the head end of the inner core shaft 7 by screws. The push rod 2, the inner core shaft 7, the traction mechanism ladder cylinder 8 and the outer die ring 10 are coaxial.

[0029] The internal cross-sectional geometry and size of the cylindrical workpiece 5 are consistent with those of the inner core shaft 7. The surface of the inner core shaft 7 is processed with grooves that are consistent with the geometric shape of the ribs of the cylindrical workpiece 5. The cylindrical workpiece 5 is assembled to the inner core shaft 7, and the cylindrical workpiece with inner ribs is sleeved on the inner core shaft to form a combination, and the appearance and geometric size of the ribs are ensured not to change. The rear end of the cylindrical workpiece 5 is in contact with the baffle 4. The push rod 2 is used to push the inner core shaft 7 into the outer die ring 10, and the traction mechanism ladder cylinder 8 is used to pull the inner core shaft 7 and the cylindrical workpiece 5 through the outer die ring 10, so that the cylindrical wall of the cylindrical workpiece 5 is plastically deformed under the extrusion of the inner wall of the outer die ring 10 and the outer wall of the inner core shaft 7, so as to achieve the effect of radial thinning.

[0030] An embodiment of the present invention provides a method for thinning a cylindrical workpiece with internal ribs. The method is implemented by using the above-mentioned plastic processing mechanism for the cylindrical workpiece with internal ribs. The method comprises the following steps:

[0031] Step 1: Install the baffle 4 to the tail end of the inner core shaft 7, install the outer die ring 10 into the die base 6, and extend the traction mechanism step cylinder 8 to one side of the die base 6;

[0032] Step 2: transport the ribbed cylindrical workpiece 5 to a heating furnace, wait for heating to a preset temperature and maintain it for a preset time;

[0033] Step three, lift the heated cylindrical workpiece 5 and put it into the inner core shaft 7 to form an assembly, connect the push rod 2 with the tail end of the inner core shaft 7, and push the head end of the inner core shaft 7 through the outer die ring 10 through the push rod 2; connect the traction mechanism step cylinder 8 with the head end of the inner core shaft 7, start the traction mechanism step cylinder 8 and the push rod 2 at the same time, and the traction mechanism step cylinder 8 contracts to drive the assembly to pass through the die hole of the outer die ring 10, and compress and thin the wall thickness of the cylindrical workpiece 5 under the extrusion action of the inner wall of the outer die ring 10 and the outer wall of the inner core shaft 7; wait for the baffle 4 to move to one side of the die base 6, and the traction mechanism step cylinder 8 and the push rod 2 stop working, and complete the single-pass thinning deformation of the ribbed cylindrical workpiece 5;

[0034] Step 4: The step cylinder 8 of the traction mechanism extends and the push rod 2 returns to drive the assembly to exit the outer die ring 10, the push rod 2 is disconnected from the inner core shaft 7, the assembly is taken out and the cylindrical workpiece 5 is unloaded;

[0035] Step 5, replace the outer die ring 10 with different apertures, repeat steps 1 to 4, and complete the wall thinning of the cylindrical workpiece with inner ribs.

[0036] It can be seen from the above embodiments that the thinning method for cylindrical workpieces with inner ribs uses a traction mechanism telescopic oil cylinder to pull the assembly through the outer die ring die hole. The stress state of the cylindrical workpiece with inner ribs in the gap between the outer wall of the inner mandrel and the inner wall of the outer die ring is a three-dimensional compressive stress, which avoids the deformation defects such as drawing cracks caused by the different axial tensile stresses on the cross-section of the cylindrical workpiece with inner ribs during the conventional long rod mandrel drawing process. At the same time, under the action of compressive stress, microscopic defects such as looseness and shrinkage of the cylinder are eliminated and a fine grain strengthening effect is achieved. Under the condition that the workpiece has a complex cross-sectional feature of large ribs and a high wall thickness ratio and a large diameter, the wall thickness of the cylindrical workpiece with inner ribs is effectively reduced, thereby improving the processing accuracy, yield rate and mechanical properties of the cylindrical workpiece.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plastic processing mechanism for a cylindrical workpiece with internal ribs, characterized in that: include: A head seat (1), a push rod (2), a baffle (4), a die seat (6), an inner core shaft (7), a traction mechanism step cylinder (8), a tail seat (9) and an outer die ring (10); The head seat (1), the die seat (6) and the tail seat (9) are arranged in parallel and spaced apart in sequence; the push rod (2) is arranged on the head seat (1) and can move in the horizontal direction, and an outer die ring (10) is arranged in the die seat (6); the traction mechanism ladder cylinder (8) is arranged on the tail seat (9); the baffle (4) is installed at the tail end of the inner core shaft (7), and the tail end of the inner core shaft (7) is connected and fixed to the push rod (2); the traction mechanism ladder cylinder (8) is connected to the head end of the inner core shaft (7); the internal cross-sectional geometric shape and size of the cylindrical workpiece (5) are consistent with those of the inner core shaft (7), the cylindrical workpiece (5) is assembled to the inner core shaft (7), and the tail end of the cylindrical workpiece (5) contacts the baffle (4); the push rod (2) is used to push the inner core shaft (7) into the outer die ring (10), and the traction mechanism ladder cylinder (8) is used to pull the inner core shaft (7) and the cylindrical workpiece (5) through the outer die ring (10).

2. A plastic processing mechanism for a cylindrical workpiece with internal ribs as claimed in claim 1, characterized in that: The head seat (1), the die seat (6) and the tail seat (9) are connected and reinforced by a frame support rod (3).

3. A plastic processing mechanism for a cylindrical workpiece with internal ribs as claimed in claim 1, characterized in that: The push rod (2), the inner core shaft (7), the traction mechanism step cylinder (8) and the outer mold ring (10) are coaxial.

4. A plastic processing mechanism for a cylindrical workpiece with internal ribs as claimed in claim 1, characterized in that: The surface of the inner core shaft (7) is processed with grooves that are consistent with the geometric shape of the ribs of the cylindrical workpiece (5).

5. A method for thinning a cylindrical workpiece with internal ribs, characterized in that: The method is implemented by using the plastic processing mechanism for a cylindrical workpiece with internal ribs as claimed in claim 1, and the method comprises the following steps: Step 1: Install the baffle (4) to the tail end of the inner core shaft (7), install the outer die ring (10) into the die base (6), and extend the traction mechanism step cylinder (8) to one side of the die base (6); Step 2, transporting the ribbed cylindrical workpiece (5) to a heating furnace, waiting for heating to a preset temperature and maintaining it for a preset time; Step three, hoisting the heated cylindrical workpiece (5) into the inner core shaft (7) to form a combination, connecting the push rod (2) to the rear end of the inner core shaft (7), and pushing the head end of the inner core shaft (7) through the outer die ring (10) through the push rod (2); connecting the traction mechanism ladder cylinder (8) to the head end of the inner core shaft (7), starting the traction mechanism ladder cylinder (8) and the push rod (2) at the same time, the traction mechanism ladder cylinder (8) contracts to drive the combination to pass through the die hole of the outer die ring (10), and compressing and thinning the wall thickness of the cylindrical workpiece (5) under the extrusion action of the inner wall of the outer die ring (10) and the outer wall of the inner core shaft (7); waiting for the baffle (4) to move to one side of the die base (6), the traction mechanism ladder cylinder (8) and the push rod (2) stop working, and complete the single-pass thinning deformation of the ribbed cylindrical workpiece (5); Step 4: The step cylinder (8) of the traction mechanism extends and the push rod (2) returns to drive the assembly to exit the outer die ring (10), the push rod (2) is disconnected from the inner core shaft (7), the assembly is taken out and the cylindrical workpiece (5) is removed; Step 5, replacing the outer die ring (10) with different apertures, repeating steps 1 to 4, and completing the wall thinning of the cylindrical workpiece with inner ribs.

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