A VGR rack swing rolling blank end limit device and its application

Abstract

The present invention discloses a device for limiting the ends of a VGR rack swing rolling blank and its application. The device comprises: end concave-convex surfaces are respectively provided at both ends of the prefabricated blank, and a movable pad concave-convex surface is provided on the movable pad. The movable pad concave-convex surfaces provided on the two movable pads respectively limit the rotation of the end concave-convex surfaces matched therewith, and the movable pad and the prefabricated blank are abutted or separated to achieve the fixation or separation of the prefabricated blank. The application method of the device comprises the steps of prefabricated blank, sandblasting, film treatment, swing rolling forming and taking out. The device prevents the product from swinging with the mold during the VGR rack forming process by radial and axial fixation. By using this method, the tooth shape accuracy, stability and production efficiency of the product can be improved under the premise of fully using materials and ensuring the mechanical properties of the product.

Description

Technical Field

[0001] The invention relates to the technical field of automobile parts production, in particular to a VGR rack swing rolling blank positioning device and application thereof. Background Art

[0002] The automobile steering system is a mechanism used to change or maintain the direction of the car's driving, ensuring that the car can turn and drive according to the driver's will. The steering gear assembly is an important part of the automobile steering system. Common steering gears include gear rack type, worm crank pin type and recirculating ball type. Gear rack steering gears are widely used in automobiles due to their simple and compact structure and high transmission efficiency. Since the steering gear is used frequently during the driving process of the car and the working conditions are complex, it is easy to produce abnormal noise. Among them, the abnormal noise generated during the meshing process of the steering gear and the steering rack is particularly obvious. When the vibration frequency of the steering gear and the steering rack when they are meshed is close to or the same as the frequency of the steering gear assembly itself, resonance will occur and abnormal noise will be emitted. This affects the comfort of the user and reduces the quality of the entire vehicle.

[0003] Traditional automobile steering gear racks have a constant transmission ratio and equidistant teeth, which are called CGR racks. They are generally manufactured using cutting methods such as tooth drawing or milling. With the development of automobile technology, variable transmission ratio steering gears have been widely used abroad and are gradually being used in China. The rack pitch changes according to the transmission ratio curve, which is called VGR rack. At present, variable pitch racks are completely dependent on imports. The domestic VGR rack process cannot position the blank during the swing rolling process, resulting in slow expansion of the swing rolling process technology. The domestic racks of existing steering gears are all CGR products, which can no longer meet the needs of steering gear variable transmission ratios.

[0004] In the process of developing the VGR rack swing rolling process, if there is no suitable positioning structure between the blank and the mold, the blank will swing with the movable mold, resulting in problems such as failure to fill the teeth smoothly, distortion of the tooth tops, and low tooth shape accuracy, making it difficult to obtain qualified VGR rack products. Summary of the invention

[0005] Purpose of the invention: In order to solve the deficiencies of the prior art, the present invention provides a blank positioning device for a VGR rack swing rolling process and its application. By using this blank, the blank will not swing with the mold when the VGR tooth shape is swing rolled. This method improves the product tooth shape accuracy, stability and production efficiency under the premise of fully utilizing materials and ensuring the mechanical properties of the product.

[0006] Technical solution: In order to achieve the above purpose, the present invention discloses a VGR rack swing rolling blank end limiting device, which comprises: an upper die, a lower die located below the upper die, a prefabricated blank located between the upper die and the lower die, a lower die template installed below the lower die, a lower die ejector rod passing through the lower die and the lower die template, a lower slider located below the lower template, a lower die ejector rod pad installed below the lower die ejector rod and abutting against a machine ejector rod passing through the lower slider, the two ends of the prefabricated blank are respectively provided with end concave-convex surfaces, the concave-convex surfaces of the movable pads provided on the two movable pads respectively limit the rotation of the end concave-convex surfaces matched therewith, and the movable pads and the prefabricated blank are abutted or separated to achieve the fixation or separation of the prefabricated blank;

[0007] The movable pad is fastened to the transmission rod, and the transmission rod is connected to the hydraulic control system, pneumatic control system or mechanical transmission system that provides power. When the preform needs to be axially fixed, the PLC circuit controls the transmission rod to push the movable pad so that one end face of the preform is close to the inner side of the movable pad. The PLC circuit controls another transmission rod to continue to extend so that the movable pad connected to the transmission rod and the other end face of the preform are against each other, thus achieving the axial positioning of the preform. When the swing rolling process is completed and the product needs to be taken out, the PLC circuit sends a signal to control the transmission rod connected to the hydraulic control system, pneumatic control system or mechanical transmission system to reset, so that the movable pad is separated from the end of the preform, and the product can be ejected by the ejector rod;

[0008] As a further preferred embodiment of the present invention, the concave-convex surface of the end portion and the concave-convex surface of the movable pad are respectively provided with one or more triangular, square, fan-shaped, revolving surface or a combination thereof grooves or convex blocks.

[0009] As a further preferred embodiment of the present invention, the angle of the triangular or fan-shaped groove or protrusion is 40° to 70°.

[0010] As a further preference of the present invention, the areas of the concave and convex surfaces of the concave end portion and the concave and convex surfaces of the movable pad block account for 40%-60% of the end surface area of ​​the preform. This ratio makes the connection of the preform into the lower die more stable and reliable, ensuring that the blank will not swing with the mold when the VGR tooth shape is swung, thereby achieving radial limitation of the preform.

[0011] As a further preferred embodiment of the present invention, the concave-convex surfaces of the movable pads provided on the two movable pads are respectively adapted to the shapes of the concave-convex surfaces of the matching end portions.

[0012] An application method of a VGR rack swing rolling blank end limit device, characterized in that the specific steps of the method are as follows:

[0013] Step 1: Prefabrication

[0014] The preformed blank is obtained by forging, extrusion or milling;

[0015] Step 2: Sandblasting

[0016] After the prefabricated blank is sandblasted, the prefabricated blank is sandblasted by a sandblasting machine to remove the oxide scale and attachments on the surface of the bar;

[0017] Step 3: Film treatment

[0018] Performing film treatment on the prefabricated blank after sandblasting;

[0019] Step 4: Rolling and forming

[0020] The preformed blank after the film treatment is placed in the mold cavity of the lower mold, and the PLC circuit controls the concave-convex surface of the movable pad on the movable pad connected to the transmission rod to be clamped into the concave-convex surface of the end of the preformed blank and push the preformed blank to a limited position. After the hydraulic control system receives the signal from the PLC circuit, the concave-convex surface of the movable pad on the movable pad connected to the transmission rod is clamped into the concave-convex surface of the other end of the preformed blank to achieve radial positioning of the preform, and the two movable pads are abutted against the two ends of the preform, so that the movable pads can achieve axial positioning of the preformed blank;

[0021] When the lower slider drives the lower die to move, the upper die starts to swing until the upper die contacts the preform, and the swing forming begins. The upper die is provided with a tooth shape corresponding to the VGR tooth shape.

[0022] When the upward stroke of the lower slider reaches the set height, the swing forming stops, and the surface of the prefabricated blank is swung to form the required VGR tooth shape, which is the finished product;

[0023] Step 5: Take out

[0024] After the finished product is obtained, the PLC circuit sends a signal to the hydraulic control system to control the two transmission rods to drive the movable pads to reset, the movable pads are separated from the finished product, the lower slide drives the lower die to move downward, and the machine table ejector drives the lower die ejector rod pad and the lower die ejector rod to move toward the upper die to eject the finished product.

[0025] As a further preferred embodiment of the present invention, the coating treatment in step three is a treatment process in which the sandblasted preform is immersed in a phosphating solution for 30 to 60 minutes to deposit a layer of water-insoluble crystalline phosphate conversion film on the surface of the preform.

[0026] As a further preferred embodiment of the present invention, the hydraulic control system, the pneumatic control system or the mechanical transmission system, the upper mold and the lower slide block are respectively connected to the PLC circuit.

[0027] Beneficial effects: The VGR rack swing rolling process blank positioning device and its application described in the present invention prevents the product from swinging with the mold through radial and axial fixation during the VGR rack forming process. By using this fixing method, the product tooth shape accuracy, stability and production efficiency can be improved under the premise of fully utilizing materials and ensuring the mechanical properties of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of the prefabricated blank;

[0029] Figure 2 It is the left view of the concave and convex surface of the end;

[0030] Figure 3 It is the right side view of the fixed pad;

[0031] Figure 4 This is a full-section front view of the fixed pad;

[0032] Figure 5 It is a partial cross-sectional view of the lower die;

[0033] Figure 6 It is a partial enlarged view of the concave and convex surfaces when they are matched;

[0034] Figure 7 This is the main view of the working status before the swing roller;

[0035] Figure 8 It is the left view of the working status after the swing roller. DETAILED DESCRIPTION

[0036] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0037] As shown in the accompanying drawings, a VGR rack swing rolling blank end limiting device described in the present invention includes: a preformed blank 1, an end concave-convex surface 11, an upper mold 10, a lower mold 20, a lower mold plate 30, a lower mold ejector rod 40, a lower mold ejector rod pad 50, a movable pad 70, a movable pad concave-convex surface 701, a lower slider 80 and a machine table ejector rod 90.

[0038] The preform 1 is located in the middle of the upper die 10 and the lower die 20, the lower die plate 30 is installed below the lower die 20, the lower die ejector rod 40 is passed through the lower die 20 and the lower die plate 30, the lower slider 80 is located below the lower die plate 30, the lower die ejector rod pad 50 is installed below the lower die ejector rod 40 and abuts against the machine push rod 90 passed through the lower slider 80, and the two ends of the preform 1 are respectively provided with end concave-convex surfaces 11, and the movable pad concave-convex surfaces 701 provided on the two movable pads 70 respectively limit the rotation of the end concave-convex surfaces 11 matched therewith, and the movable pad 70 is fastened to the transmission rod, and the transmission rod is connected to the hydraulic control system, pneumatic control system or mechanical transmission system that provides power.

[0039] Example 1

[0040] Step 1: Prefabrication

[0041] A preformed blank 1 is obtained by forging, extruding or milling;

[0042] Step 2: Sandblasting

[0043] The prefabricated blank 1 is sandblasted by a sandblasting machine to remove the oxide scale and attachments on the surface of the bar;

[0044] Step 3: Film treatment

[0045] The preform 1 after the sandblasting treatment is subjected to a film treatment, wherein the film treatment is a process in which the preform 1 after the sandblasting treatment is immersed in a phosphating solution for 30 minutes to deposit a layer of water-insoluble crystalline phosphate conversion film on the surface of the preform 1;

[0046] Step 4: Rolling and forming

[0047] The preform 1 after the film treatment is placed in the mold cavity of the lower mold 20, and the PLC circuit controls the transmission rod connected to the hydraulic control system to work. The transmission rod pushes the movable pad 70, so that the movable pad concave-convex surface 701 on the movable pad 70 is stuck into the end concave-convex surface 11 of the preform 1 and the preform 1 is pushed to a limited position. After the hydraulic control system receives the signal from the PLC circuit, the movable pad concave-convex surface 701 on the movable pad 70 connected to the transmission rod is stuck into the other concave-convex surface 11 on the preform 1. The end concave-convex surface 11 is provided to realize radial positioning of the preform 1. The two movable pads 70 are abutted against the two ends of the preform 1 to realize axial positioning of the preform 1 by the movable pads 70. A triangular groove is provided on the end concave-convex surface 11, and a triangular convex block is provided on the concave-convex surface 601 and the movable pad concave-convex surface 701 respectively. The positions of the triangular groove and the triangular convex block are opposite, and the area of ​​the triangular groove and the triangular convex block accounts for 40% of the end surface area of ​​the preform 1. The angle between the triangular groove and the triangular convex block is 40°.

[0048] At this time, after the transmission rod moves to the limited position, the PLC circuit sends a signal to the lower slider 30, and after the lower slider 30 drives the lower die 20 to move upward, the upper die 10 receives the signal sent by the PLC circuit and starts to swing until the upper die 10 contacts the preform 1, and the swing forming begins. The upper die 10 is provided with a tooth shape corresponding to the VGR tooth shape;

[0049] When the upward stroke of the lower slider 30 reaches the set height, the swing forming stops, and the surface of the preform 1 swings out the required VGR tooth shape, which is the finished product 2;

[0050] Step 5: Take out

[0051] After the finished product 2 is obtained, the PLC circuit sends a signal to the hydraulic control system to control the two transmission rods to drive the movable pad 70 to reset, the movable pad 70 is separated from the finished product, the lower slide block 30 drives the lower mold 20 to move downward, and the machine push rod 90 drives the lower mold push rod pad 50 and the lower mold push rod 40 to move toward the upper mold 10 to eject the finished product 2.

[0052] Example 2

[0053] Step 1: Prefabrication

[0054] A preformed blank 1 is obtained by forging, extruding or milling;

[0055] Step 2: Sandblasting

[0056] The prefabricated blank 1 is sandblasted by a sandblasting machine to remove the oxide scale and attachments on the surface of the bar;

[0057] Step 3: Film treatment

[0058] The preform 1 after the sandblasting treatment is subjected to a film treatment, wherein the film treatment is a process in which the preform 1 after the sandblasting treatment is immersed in a phosphating solution for 60 minutes to deposit a layer of water-insoluble crystalline phosphate conversion film on the surface of the preform 1;

[0059] Step 4: Rolling and forming

[0060] The preform 1 after film treatment is placed in the mold cavity of the lower mold 20, and the PLC circuit controls the transmission rod connected to the pneumatic control system to work. The transmission rod pushes the movable pad 70, so that the movable pad concave-convex surface 701 of the movable pad 70 is stuck into the end concave-convex surface 11 on the preform 1 and the preform is pushed to a limited position. After the pneumatic control system receives the signal from the PLC circuit, another transmission rod connected to the pneumatic control system causes the movable pad concave-convex surface 701 on the movable pad 70 connected to the transmission rod to be stuck into the end concave-convex surface 11 on the preform 1. The other end concave-convex surface 11 realizes radial positioning of the preform 1. The two movable pads 70 are against the two ends of the preform 1, so that the movable pads 70 can position the preform 1 axially. The end concave-convex surface 1 is provided with two fan-shaped protrusions. The end concave-convex surface 11 and the movable pad concave-convex surface 701 are respectively provided with two fan-shaped grooves. The two fan-shaped protrusions and the two fan-shaped grooves are located opposite to each other. The area of ​​the fan-shaped groove and the fan-shaped protrusion accounts for 60% of the end surface area of ​​the preform 1. The angle between the fan-shaped groove and the fan-shaped protrusion is 70°.

[0061] At this time, after the transmission rod moves to the limited position, the PLC circuit sends a signal to the lower slider 30, and after the lower slider 30 drives the lower die 20 to move upward, the upper die 10 receives the signal sent by the PLC circuit and starts to swing until the upper die 10 contacts the preform 1, and the swing forming begins. The upper die 10 is provided with a tooth shape corresponding to the VGR tooth shape;

[0062] When the upward stroke of the lower slider 30 reaches the set height, the swing forming stops, and the surface of the preform 1 swings out the required VGR tooth shape, which is the finished product 2;

[0063] Step 5: Take out

[0064] After the finished product 2 is obtained, the PLC circuit sends a signal to the pneumatic control system to control the two transmission rods to drive the movable pad 70 to reset, the movable pad 70 is separated from the finished product, the lower slide block 30 drives the lower mold 20 to move downward, and the machine push rod 90 drives the lower mold push rod pad 50 and the lower mold push rod 40 to move toward the upper mold 10 to eject the finished product 2.

[0065] Example 3

[0066] Step 1: Prefabrication

[0067] A preformed blank 1 is obtained by forging, extruding or milling;

[0068] Step 2: Sandblasting

[0069] The prefabricated blank 1 is sandblasted by a sandblasting machine to remove the oxide scale and attachments on the surface of the bar;

[0070] Step 3: Film treatment

[0071] The preform 1 after the sandblasting treatment is subjected to a film treatment, wherein the film treatment is a process in which the preform 1 after the sandblasting treatment is immersed in a phosphating solution for 30 minutes to 60 minutes to deposit a layer of water-insoluble crystalline phosphate conversion film on the surface of the preform 1;

[0072] Step 4: Rolling and forming

[0073] The preform 1 after film treatment is placed in the mold cavity of the lower mold 20, and the PLC circuit controls the transmission rod connected to the mechanical transmission system to work. The transmission rod pushes the movable pad 70, so that the movable pad concave-convex surface 701 on the movable pad 70 is stuck into the end concave-convex surface 11 on the preform 1 and pushes the preform to a defined position. After the pneumatic control system receives the signal from the PLC circuit, another transmission rod connected to the mechanical transmission system moves the movable pad concave-convex surface 701 on the movable pad 70 connected to the transmission rod. 1 is inserted into the other end concave-convex surface 11 of the preform 1 to realize radial positioning of the preform 1. The two movable pads 70 are against the two ends of the preform 1 to realize the axial positioning of the preform 1 by the movable pads 70. The end concave-convex surface 1 is provided with three square convex blocks, and the end concave-convex surface 11 and the movable pad concave-convex surface 701 are respectively provided with three square grooves. The positions of the two square convex blocks and the two square grooves are opposite, and the areas of the square grooves and the square convex blocks account for 60% of the end surface area of ​​the preform 1.

[0074] At this time, after the transmission rod moves to the limited position, the PLC circuit sends a signal to the lower slider 30, and after the lower slider 30 drives the lower die 20 to move upward, the upper die 10 receives the signal sent by the PLC circuit and starts to swing until the upper die 10 contacts the preform 1, and the swing forming begins. The upper die 10 is provided with a tooth shape corresponding to the VGR tooth shape;

[0075] When the upward stroke of the lower slider 30 reaches the set height, the swing forming stops, and the surface of the preform 1 swings out the required VGR tooth shape, which is the finished product 2;

[0076] Step 5: Take out

[0077] After the finished product 2 is obtained, the PLC circuit sends a signal to the mechanical transmission system to control the two transmission rods to drive the movable pad 70 to reset, the movable pad 70 is separated from the finished product, the lower slider 30 drives the lower mold 20 to move downward, and the machine table push rod 90 drives the lower mold push rod pad 50 and the lower mold push rod 40 to move toward the upper mold 10 to eject the finished product 2.

[0078] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A VGR rack swing rolling blank end limit device, which comprises: An upper mold (10), a lower mold (20) located below the upper mold (10), a preform (1) located between the upper mold (10) and the lower mold (20), a lower mold plate (30) installed below the lower mold (20), a lower mold ejector pin (40) passing through the lower mold (20) and the lower mold plate (30), a lower slider (80) located below the lower mold plate (30), and a lower mold ejector pin pad (50) installed below the lower mold ejector pin (40) and abutting against a machine ejector pin (90) passing through the lower slider (80), wherein: the preform The two ends of the blank (1) are respectively provided with an end concave-convex surface (11), and the movable pad (70) is provided with a movable pad concave-convex surface (701). The movable pad concave-convex surfaces (701) provided on the two movable pads (70) respectively restrict the rotation of the end concave-convex surfaces (11) matched therewith. The movable pads (70) and the preformed blank (1) are abutted against or separated to achieve the fixing or separation of the preformed blank (1). The movable pad (70) is fastened to a transmission rod, and the transmission rod is connected to a hydraulic control system, a pneumatic control system or a mechanical transmission system that provides power. The end concave-convex surface (11) and the movable pad concave-convex surface (701) are respectively provided with one or more triangular, square, fan-shaped, revolving surface or a combination thereof grooves or convex blocks, and the angle of the triangular or fan-shaped grooves or convex blocks is 40° to 70°; The hydraulic control system, pneumatic control system or mechanical transmission system, the upper die (10) and the lower slide block (80) are respectively connected to the PLC circuit.

2. A VGR rack swing rolling blank end limit device according to claim 1, characterized in that: The areas of the end concave-convex surface (11) and the movable pad concave-convex surface (701) account for 40%-60% of the end surface area of ​​the prefabricated blank (1).

3. A VGR rack swing rolling blank end limiter according to claim 1, characterized in that: The movable pad concave-convex surfaces (701) provided on the two movable pads (70) are respectively adapted to the shapes of the matching end concave-convex surfaces (11).

4. An application method of the VGR rack swing rolling blank end limit device as claimed in claim 1, characterized in that: The specific steps of this method are as follows: Step 1: Prefabrication A preformed blank (1) is obtained by forging, extrusion or milling; Step 2: Sandblasting The prefabricated blank (1) is subjected to sandblasting treatment by a sandblasting machine to remove oxide scale and attachments on the surface of the bar; Step 3: Film treatment Performing film treatment on the prefabricated blank (1) after sandblasting; Step 4: Rolling and forming The preform (1) after the film treatment is placed in the mold cavity of the lower mold (20), and the PLC circuit controls the driving rod connected to the hydraulic control system to work, and the driving rod pushes the movable pad (70) so that the movable pad concave-convex surface (701) on the movable pad (70) is clamped into the end concave-convex surface (11) of the preform (1) and the preform (1) is pushed to a limited position. After the hydraulic control system receives a signal from the PLC circuit, another driving rod connected to the hydraulic control system causes the movable pad concave-convex surface (701) on the movable pad (70) connected to the driving rod to be clamped into the other end concave-convex surface (11) of the preform (1); When the lower slider (80) drives the lower die (20) to move upward, the upper die (10) starts to swing until the upper die (10) contacts the preform (1), and the swing forming begins. The upper die (10) is provided with a tooth shape corresponding to the VGR tooth shape. When the upward movement of the lower slider (80) reaches the set height, the swing forming stops, and the surface of the preform (1) is swing-rolled to form the required VGR tooth shape, which is the finished product (2); Step 5: Take out After the finished product (2) is obtained, the PLC circuit sends a signal to the hydraulic control system to control the two transmission rods to drive the movable pad (70) to reset, the movable pad (70) is separated from the finished product, the lower slide block (80) drives the lower mold (20) to move downward, and the machine table ejector rod (90) drives the lower mold ejector rod pad (50) and the lower mold ejector rod (40) to move toward the upper mold (10) to eject the finished product.

5. The application method of the VGR rack swing rolling blank end limit device according to claim 4 is characterized in that: The coating treatment in step 3 is a process in which the sandblasted preform (1) is immersed in a phosphating solution for 30 minutes to 60 minutes to deposit a layer of water-insoluble crystalline phosphate conversion film on the surface of the preform (1).

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