Agricultural machinery steering axle tube beam formed by seamless steel tube and manufacturing method thereof

Abstract

The invention discloses an agricultural machinery steering axle tube beam formed by a seamless steel tube and a manufacturing method thereof, and relates to the technical field of engineering machinery parts, the agricultural machinery steering axle tube beam is of a symmetrical variable cross-section variable wall thickness hollow rectangular structure, is composed of a tube beam middle part, a tube beam neck part and tube beam two ends, and is in an inverted convex shape with a flush upper surface, consistent width and a raised middle lower part. The middle size of the tubular beam meets performance requirements and oil cylinder support mounting requirements, and a round hole for mounting a supporting bearing seat is formed in the tubular beam; the lower surfaces of the two ends of the tubular beam are higher, and arc-shaped grooves welded with main pin seats are formed in the outer sides; the upper surface and the width of the neck of the tubular beam are unchanged, and the lower surface gradually rises through two transition arcs and is connected with the middle of the tubular beam and the two ends of the tubular beam respectively. The pipe beam is manufactured by heating, reducing, bending, pressing and machining a seamless steel pipe, the impact resistance of a product is good, the weight is reduced by more than 15% compared with that of a welding structure, the material utilization rate reaches 95%, and the universality is high.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery components, and more specifically, to an agricultural machinery steering bridge pipe beam formed by seamless steel pipe and its manufacturing method. Background Art

[0002] The agricultural machinery steering bridge is one of the important load-bearing components of the agricultural machinery chassis. During operation, the steering bridge needs to bear the load generated by the uneven road surface, so it is required to have high strength, stiffness and fatigue life. The main body of the agricultural machinery steering bridge is the steering bridge pipe beam.

[0003] Currently, the agricultural machinery steering bridge pipe beam is divided into two forms according to the manufacturing process: steel plate stamping and welding type and steel pipe welding type.

[0004] See Figure 1 As shown, the steel plate stamping and welding type agricultural machinery steering bridge includes a steering bridge pipe beam and two main pin seats welded at both ends. The steering bridge pipe beam is welded by an upper plate, a lower plate, a front side plate and a rear side plate, and the upper plate is in a bent shape. This kind of steering bridge pipe beam has many manufacturing processes, many welding parts, long welds, high welding quality requirements, weak impact resistance and low fatigue life, and is mainly applied to agricultural harvesters with small axle loads.

[0005] See Figure 2 As shown, the steel pipe welded type agricultural machinery steering bridge, in which the steering bridge pipe beam is composed of a square steel pipe welded with a U-shaped reinforcing plate. Compared with the steel plate stamping and welding type agricultural machinery steering bridge pipe beam, the steel pipe welded type has fewer weld numbers and lengths, and its impact resistance and fatigue life are improved.

[0006] The agricultural machinery steering bridge pipe beam with a welded structure has welds in its structure, and there are still deficiencies in the strength, stiffness and lightweight of the product. Summary of the Invention

[0007] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide an agricultural machinery steering bridge pipe beam formed by seamless steel pipe and its manufacturing method.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is: an agricultural machinery steering bridge pipe beam formed by seamless steel pipe, including the middle part of the pipe beam, and the two ends of the middle part of the pipe beam are respectively connected with the end parts of the pipe beam. The agricultural machinery steering bridge pipe beam is a variable cross-section and variable wall-thickness hollow structure formed by pressing seamless steel pipe, and the whole is in an inverted "convex" shape with a flat upper surface, consistent width and a bulge below the middle part; The length of the middle part of the pipe beam is L0, the cross-sectional height is h1, the width is b1, and the wall thickness is t1, and the height-width ratio h1 / b1 of the cross-section is 1.5 - 2.2; a through-round hole is opened in the middle part of the pipe beam, the diameter of the round hole is d1, which is used to install the support bearing seat, and the distance from the center of the round hole to the upper surface of the middle part of the pipe beam is H1, and the distance from the center plane of the pipe beam is H2;​ The cross-sectional height of the end of the pipe beam is h2, the width is b2, and the wall thickness is t2, with width b2=b1 and wall thickness t2>t1; the end of the pipe beam is flush with the upper plane of the middle part of the pipe beam, and the lower plane is higher than the lower plane of the middle part of the pipe beam, with a height difference of H3; an inwardly inclined arc groove with an angle of θ2 is provided on the outer side of the end of the pipe beam, the groove depth is H4, and the radius is R3, which facilitates the welding of the master pin seat; the horizontal distance between the outer sides of the two ends of the pipe beam is L1; The two ends of the middle section of the tube beam are connected to the corresponding ends of the tube beam through the tube beam neck; the cross-sectional width and upper surface position of the tube beam neck remain unchanged, while the lower surface is gradually raised through two transition arcs; the radius of the transition arc on the lower surface at the connection between the tube beam neck and the middle section of the tube beam is R1, and the bending angle is θ1; the radius of the transition arc on the lower surface at the connection between the tube beam neck and the end of the tube beam is R2, and the bending angle is the same as θ1, but the bending direction is opposite.

[0009] The present invention also provides a method for manufacturing the above-mentioned seamless steel pipe forming agricultural machinery steering bridge tube beam, comprising the following steps: step S1. selecting tube blank; step S2. heating; step S3. diameter reduction; step S4. bending; step S5. pressing; step S6. machining.

[0010] Based on the above technical solution, the initial tube blank length L1 is equal to that of the tube beam product; the outer diameter d2 of the tube blank is determined according to the principle that its outer surface perimeter is equal to the outer surface perimeter of the rectangular section in the middle of the product tube beam; the tube blank wall thickness t1 is equal to the wall thickness in the middle of the product tube beam.

[0011] Based on the above technical solution, the two ends of the tube blank are heated to 800°C using a medium-frequency induction heating furnace. The length of the heating zone is L2, and the heating zone is finally formed into the tube beam end and tube beam neck of the product.

[0012] Based on the above technical solution, the heating part is reduced in diameter. The outer diameter of the reduced part is d3, and the wall thickness is increased to t2. The reduced part transitions to the middle conical part with a half-cone angle of θ3 and a transition arc size of R4.

[0013] Based on the above technical solution, the tube blank after diameter reduction is bent to obtain a pre-formed tube blank with a hollow circular cross section; the middle section of the circular tube is L3 in length, and this part is finally formed into the middle part of the tube beam; the center lines on both sides of the circular tube are raised upward by H5, so that the upper and lower surfaces form a height difference H6 and H7; the bending angle of the transition zone of the upper surface is θ4 and the radius of the transition arc is R5; the bending angle of the transition zone of the lower surface is θ5 and the radius of the transition arc is R6.

[0014] On the basis of the above technical solution, a three-way hydraulic press and a pressing die are used to integrally press and form a preformed tube blank from above and the front and back sides to obtain a steering bridge tube beam fitting; the fitting is a symmetric variable cross-section hollow rectangular structure, and the appearance is an inverted "convex" shape with a flat upper surface, the same width, and a bulge below the middle; the middle part of the tube beam is a hollow rectangular tube with a length of L0, a cross-sectional dimension of h1×b1, and a wall thickness of t1; the cross-sectional dimension of the end part of the tube beam is h2×b2, and the wall thickness is t2; the middle part of the tube beam is connected to the end part of the tube beam through a tube beam neck, the width of the cross-section of the tube beam neck remains unchanged and the position of the upper surface remains unchanged, and the lower surface gradually rises through two transition arcs.

[0015] On the basis of the above technical solution, a circular hole penetrating through the front and back is machined in the middle part of the tube beam, the diameter of the circular hole is d1, the distance between the center of the circular hole and the upper surface of the middle part of the tube beam is H1, and the distance from the center symmetry plane of the whole tube beam is H2; an arc groove with an inward inclination angle of θ2 is machined on the outer side of the end part of the tube beam, the depth of the arc opening is H4, and the arc radius is R3; the final horizontal length of the product is L1.

[0016] The beneficial effects of the present invention are as follows: (1) The agricultural machinery steering bridge tube beam provided by the present invention adopts a seamless steel tube integrally formed variable cross-section and variable wall thickness hollow rectangular structure, eliminating the weld seam and effectively improving the impact resistance.

[0017] (2) The agricultural machinery steering bridge tube beam provided by the present invention reduces the weight by more than 15% compared with the traditional welded structure product, and at the same time, the material utilization rate reaches more than 95%.

[0018] (3) The manufacturing method of the agricultural machinery steering bridge tube beam provided by the present invention uses the same reducing, bending, and pressing dies, and by changing the wall thickness and length of the initial tube blank, platform products of multiple specifications can be manufactured, having good versatility. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of a certain steel plate stamping and welding agricultural machinery steering bridge in the prior art; Figure 2 is a schematic structural diagram of a certain steel pipe welded agricultural machinery steering bridge in the prior art; Figure 3 is the front view of the agricultural machinery steering bridge tube beam in the present invention; Figure 4 is the top view of the agricultural machinery steering bridge tube beam in the present invention; Figure 5 is a schematic diagram of the initial tube blank of the agricultural machinery steering bridge tube beam in the present invention; <00000​​​It is the preformed tube blank after bending of the agricultural machinery steering bridge tube beam in this invention; Figure 8 This is a front view of the pipe beam fittings after the agricultural machinery steering bridge pipe beam has been pressed in this invention; Figure 9 This is a top view of the pressed tube beam fittings for the agricultural machinery steering axle in this invention.

[0020] Figure 10 This is a front view of the 3t single-sided hydraulic cylinder agricultural machinery steering axle of the present invention; Figure 11 This is a front view of the 4t single-sided hydraulic cylinder agricultural machinery steering axle of the present invention; Figure 12 This is a front view of the 4t two-sided hydraulic cylinder agricultural machinery steering axle in this invention.

[0021] Figure label: 1-End of tube beam; 2-Neck of tube beam; 3-Middle of tube beam. Detailed Implementation

[0022] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0023] In the description of this invention, it should be noted that the directional terms such as "center", "lateral (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0024] The following description, in conjunction with the accompanying drawings, further illustrates specific embodiments of the present invention, making the technical solution and its beneficial effects clearer and more explicit. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the invention.

[0025] See Figure 3 and Figure 4As shown, this embodiment of the invention provides a seamless steel pipe forming agricultural machinery steering bridge tube beam with an axle load of 4t. The tube beam is formed from steel pipe and includes a left end, a left neck, a middle part 3, a right neck, and a right end connected in sequence. The left end, left neck, middle part 3, right neck, and right end are integrally formed variable cross-section and variable wall thickness hollow structures.

[0026] The left and right ends of the tube beam have the same structure; to distinguish them, they can be simply referred to as tube beam end 1. The left and right necks have the same structure; to distinguish them, they can be simply referred to as tube beam neck 2.

[0027] The length of the middle section 3 of the tube beam is L0=680mm, the section height is h1=180mm, the width is b1=100mm, and the wall thickness is t1=7mm. The middle section 3 of the tube beam has a circular hole that runs through the front and back. The diameter of the circular hole is d1=60mm, which is used to install the support bearing seat. The distance between the center of the circular hole and the upper surface of the middle section of the tube beam is H1=49mm, and the distance between the center of the circular hole and the center surface of the tube beam is H2=25mm.

[0028] The end section of the pipe beam has a height of h2=130mm, a width of b2=100mm, and a wall thickness of t2=8mm. The end section of the pipe beam is flush with the upper plane of the middle section of the pipe beam, and the lower plane is higher than the lower plane of the middle section of the pipe beam, with a height difference of H3=50mm. There is an inwardly inclined arc groove on the left side of the left end of the pipe beam with an inward angle of θ2=5°, a groove depth of H4=29.5mm, and a radius of R3=44.5mm, which facilitates the welding of the master pin seat. The right end of the pipe beam is symmetrical to the left end of the pipe beam about the center plane of the pipe beam. The horizontal distance between the outer sides of the two ends of the pipe beam is L1=1520mm.

[0029] The middle section 3 of the tube beam is connected to the end section 1 of the tube beam through the neck 2 of the tube beam; the cross-sectional width and upper surface position of the neck 2 of the tube beam remain unchanged, while the lower surface is gradually raised through two transition arcs; the right end of the left neck is connected to the middle section of the tube beam, the radius of the lower surface transition arc is R1=240mm, and the bending angle is θ1=27°; the left end of the left neck is connected to the left side of the tube beam, the radius of the lower surface transition arc is R2=240mm, and the bending angle is the same as θ1=27°, but the bending direction is opposite; the left neck and the right neck are symmetrical about the center plane of the tube beam.

[0030] See Figures 5-9 As shown, this embodiment of the invention also provides a method for manufacturing the above-mentioned seamless steel pipe forming agricultural machinery steering axle beam, comprising the following steps: Step S1. Selecting the tube blank; Step S1 specifically includes: the initial tube blank length L1=1520mm is equal to that of the tube beam product; the outer diameter of the tube blank d2=168mm is determined according to the principle that its outer surface perimeter is equal to the outer surface perimeter of the rectangular section 3 in the middle of the tube beam product; the tube blank wall thickness t1=7mm is equal to the wall thickness of the middle 3 section of the tube beam product.

[0031] Step S2. Heating; Step S2 specifically includes: heating both ends of the tube blank to 800 °C with an intermediate frequency induction heating furnace, the length of the heating zone is L2 = 300 mm, and the heating zone is finally formed into the tube beam end 1 and the tube beam neck 2 of the product.

[0032] Step S3. Reducing the diameter; Step S3 specifically includes: reducing the diameter of the heated part, the outer diameter of the reduced part is d3 = 142 mm, and the wall thickness is increased to t2 = 8 mm. The reduced part is tapered and transitioned with the middle part, the half cone angle is θ3 = 20°, and the size of the transition arc is R4 = 100 mm.

[0033] Step S4. Bending; the length of the middle section of the circular tube is L3 = 730 mm, and the middle section of the circular tube is finally formed into the middle part of the tube beam. Step S4 specifically includes: bending the tube blank after reducing the diameter to obtain a preformed tube blank with a hollow circular cross-section; the length of the middle section of the circular tube is L3 = 730 mm, and this part is finally formed into the middle part 3 of the tube beam; the center lines on both sides of the circular tube are raised upward by H5 = 20 mm, so that the height difference between the upper surface and the lower surface is H6 = 7 mm and H7 = 33 mm; the bending angle of the upper surface transition area is θ4 = 10°, and the transition arc radius is R5 = 200 mm; the bending angle of the lower surface transition area is θ5 = 20°, and the transition arc radius is R6 = 200 mm.

[0034] Step S5. Pressing; Step S5 specifically includes: using an upper three-way hydraulic press and a pressing die to integrally press and form the preformed tube blank from above and from the front and back sides to obtain a steering knuckle tube beam fitting; this fitting is a symmetric variable cross-section hollow rectangular structure, and its appearance is an inverted "convex" shape with a flat upper surface, the same width, and a bulge below the middle; the middle part 3 of the tube beam is a hollow rectangular tube with a length L0 = 680 mm, a height h1 = 180 mm, a width b1 = 100 mm, and a wall thickness of t1 = 7 mm; the height of the tube beam end 1 is h2 = 130 mm, the width is b2 = 100 mm, and the wall thickness is t2 = 8 mm; the middle part 3 of the tube beam is connected to the tube beam end 1 through the tube beam neck 2, the width of the cross-section of the tube beam neck is unchanged and the position of the upper surface is unchanged, and the lower surface gradually rises through two transition arcs.

[0035] Step S6. Machining. Step S6 specifically includes: machining a circular hole that penetrates from front to back in the middle part 3 of the tube beam, the diameter of the circular hole is d1 = 60 mm, the distance between the center of the circular hole and the upper surface of the middle part of the tube beam is H1 = 49 mm, and the distance from the center symmetry plane of the whole tube beam is H2 = 25 mm; machining an arc groove with an inward inclination angle of θ2 = 5° on the outside of the tube beam end 1, the depth of the arc opening is H4 = 29.5 mm, and the arc radius is R3 = 44.5 mm; the final horizontal length of the product is L1 = 1520 mm.

[0036] Appendix Figures 10-12The three types of agricultural machinery steering axles are 3t single-sided hydraulic cylinder, 4t single-sided hydraulic cylinder, and 4t double-sided hydraulic cylinder. When producing platform products of different specifications, only the wall thickness and length of the initial tube blank are changed, and the same set of reducing, bending, and pressing molds are used.

[0037] The steering axle provided by this invention is a steering axle structure formed by pressing seamless steel tubes. It employs a seamless steel tube integral forming process, and the entire axle adopts a hollow rectangular section with variable cross-section and wall thickness, eliminating welds and effectively improving the impact resistance of the axle; it also offers good lightweighting; material utilization is over 95%; and the molds used in its manufacture have good versatility, reducing mold manufacturing costs.

[0038] In the description of this specification, references to terms such as "an embodiment," "preferred," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. Illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] This invention is not limited to the embodiments described above. Those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A seamless steel tube formed agricultural steering axle tube beam, comprising a tube beam middle part (3), a tube beam end part (1) is connected to each end of the tube beam middle part (3), characterized in that: The agricultural machinery steering bridge pipe beam is a variable cross-section and variable wall thickness hollow structure pressed and formed by a seamless steel pipe, and has an overall inverted "U" shape with a flat upper surface, consistent width, and a raised lower middle portion; The pipe beam middle portion (3) has a length L0, a cross-section height h1, a width b1, and a wall thickness t1, and a cross-section height-width ratio h1 / b1 of 1.5-2.2; the pipe beam middle portion (3) is provided with a through hole passing through the front and rear, and the hole diameter is d1, which is used for installing a supporting bearing seat, and the distance between the hole center and the upper surface of the pipe beam middle portion (3) is H1, and the distance between the hole center and the center surface of the pipe beam is H2; The pipe beam end portion (1) has a cross-section height h2, a width b2, and a wall thickness t2, and the width b2=b1, and the wall thickness t2>t1; the pipe beam end portion (1) is flush with the upper surface of the pipe beam middle portion (3), and the lower surface is higher than that of the pipe beam middle portion (3), and the height difference is H3; the outer side of the pipe beam end portion (1) is provided with a circular arc groove with an inward inclination angle θ2, a groove depth H4, and a radius R3, which facilitates welding of the kingpin seat; the horizontal distance between the outer sides of the two pipe beam end portions (1) is L1; The pipe beam middle portion (3) is connected to the corresponding pipe beam end portion (1) through the pipe beam neck portion (2) at both ends; the cross-section width of the pipe beam neck portion (2) is constant, and the upper surface position is constant, and the lower surface is gradually raised through two transition circular arcs; the transition circular arc radius of the lower surface at the connection between the pipe beam neck portion (2) and the pipe beam middle portion (3) is R1, and the bending angle is θ1; the transition circular arc radius of the lower surface at the connection between the pipe beam neck portion (2) and the pipe beam end portion (1) is R2, and the bending angle is θ1, but the bending directions are opposite.

2. A method for manufacturing a seamless steel pipe formed agricultural swerving axle pipe beam of claim 1, characterized in that, The method comprises the following steps: Step S1. Selecting a pipe blank; Step S2. Heating; Step S3. Reducing the diameter; Step S4. Bending; Step S5. Pressing; Step S6. Machining.

3. The method of claim 2, wherein, Step S1 specifically comprises: the initial pipe blank length L1 is equal to the pipe beam product; the outer diameter d2 of the pipe blank is determined according to the principle that the outer surface circumference of the pipe blank is equal to that of the rectangular cross-section of the pipe beam middle portion (3); and the pipe blank wall thickness t1 is equal to the wall thickness of the pipe beam middle portion (3).

4. The method of claim 2, wherein, Step S2 specifically comprises: heating the two ends of the pipe blank to 800°C using a medium-frequency induction heating furnace, and the heating zone length is L2, and the heating zone is finally formed into the pipe beam end portion (1) and the pipe beam neck portion (2) of the product.

5. The method of claim 2, wherein, Step S3 specifically comprises: reducing the diameter of the heated portion, and the outer diameter of the reduced portion is d3, and the wall thickness is increased to t2, and the reduced portion is tapered to the middle portion with a half-cone angle θ3 and a transition circular arc size R4.

6. The method of claim 2, wherein, Step S4 specifically comprises: bending the reduced pipe blank to obtain a pre-formed pipe blank with a hollow circular cross-section; the middle circular pipe has a length L3, and this part is finally formed into the pipe beam middle portion (3); the center lines of the two sides of the circular pipe are raised upward by H5, so that the upper surface and the lower surface form height differences H6 and H7; the bending angle of the upper surface transition area is θ4, and the transition circular arc radius is R5; the bending angle of the lower surface transition area is θ5, and the transition circular arc radius is R6.

7. The method of claim 2, wherein, Step S5 specifically comprises: using a three-way hydraulic machine and a pressing die to integrally press and form the preformed pipe blank from the top and the front and back sides to obtain a pipe beam pipe fitting of a steering bridge; the pipe fitting is a symmetrical variable cross-section hollow rectangular structure, and the appearance is an inverted "convex" character shape with flush upper surfaces, consistent width, and a raised lower middle part; the middle part (3) of the pipe beam is a hollow rectangular tube with a length L0, a cross-sectional dimension h1×b1, and a wall thickness t1; the cross-sectional dimension of the end part (1) of the pipe beam is h2×b2, and the wall thickness is t2; the middle part (3) of the pipe beam is connected with the end part (1) of the pipe beam through a neck part (2) of the pipe beam, the width of the cross section of the neck part (2) of the pipe beam is unchanged, and the upper surface position is unchanged, and the lower surface is gradually raised through two transition circular arcs.

8. The method of claim 2, wherein, Step S6 specifically comprises: processing a circular hole through the front and back in the middle part (3) of the pipe beam, the circular hole diameter is d1, the distance from the center of the circular hole to the upper surface of the middle part (3) of the pipe beam is H1, and the distance from the center of the circular hole to the center symmetry plane of the whole pipe beam is H2; processing a circular arc groove with an inward inclination angle θ2 on the outside of the end part (1) of the pipe beam, the circular arc groove depth is H4, and the circular arc radius is R3; and the final horizontal length of the product is L1.

Images