Detection tool for detecting symmetry degree of two sides of tooth area of VGR rack

Abstract

The utility model discloses a gauge for detecting the symmetry degree of two sides of a tooth area of a VGR rack, which comprises a bottom plate, an axial supporting mechanism fixedly arranged on the bottom plate, and a radial limiting mechanism for radially limiting a workpiece placed on the axial supporting mechanism, the detection tool is simple and short in assembly process and low in manufacturing cost, and compared with a three-coordinate and contourgraph precision detection tool, the detection tool is low in professional requirement for operators, simple to operate, high in detection efficiency, high in detection accuracy, high in detection accuracy and high in detection efficiency. Products produced in a large scale can be efficiently and rapidly screened, and the testing fixture is low in manufacturing cost and suitable for mass production, application and popularization.

Description

Technical Field

[0001] The utility model relates to the field of inspection tool equipment characterized by adopting a mechanical method, in particular to an inspection tool used for inspecting the symmetry of two sides of a VGR rack tooth area. Background Art

[0002] With the development of emerging technologies, variable transmission ratio steering gears have been widely used abroad and are gradually being used in China. Traditional gear racks have a constant transmission ratio and the teeth are equidistant, which is called CGR racks. They are generally manufactured by cutting methods such as tooth drawing or milling. The rack pitch changes according to the transmission ratio curve, which is called a variable speed ratio rack or VGR rack. VGR rack is a steering system that combines a rack and a pinion. It has different gear ratios at the center and both ends of the rack. This rack with a variable speed ratio is mostly used in automobile steering systems. The variable speed ratio steering system is different from the traditional gear rack steering system. The rack on the steering linkage on the traditional gear rack steering system is uniformly dense, while the VGR rack achieves different speed ratios by adjusting the tooth profile parameters. Therefore, the VGR rack variable speed ratio tooth surface presents a curved surface.

[0003] The VGR rack processing methods in the prior art are generally organic machining and forging. Organic machining uses high-speed milling or five-axis precision carving. The machining efficiency during forging is low and the precision is high; forging has high efficiency but will cause deformation of the workpiece.

[0004] At present, the VGR rack processing methods on the market are generally organic processing and forging processing. Organic processing uses high-speed milling or five-axis precision carving; in forging processing, the machining efficiency is low, the precision is high, and the forging efficiency is high, but it will cause deformation of the workpiece. There are flash on both sides of the tooth area of ​​the VGR rack after forging, and machining is required to remove the flash residue. In order to ensure that the flash residue removed on both sides is relatively equal, the symmetry of both sides of the tooth area after machining must be detected.

[0005] At present, the traditional detection method for VGR racks in the market mainly adopts three-coordinate detection, scanning the forged VGR rack tooth area profile to detect symmetry. However, there is no special inspection tool for VGR rack tooth area profile symmetry detection in the market, and due to the high cost of three-coordinate detection, high professional requirements for detection personnel, complex detection process, difficult operation, high detection cost and other problems, VGR racks are not conducive to mass production detection.

[0006] Another example is a method for detecting the tooth height of a straight tooth face tooth disclosed in Chinese patent CN 114061401 A: measuring the center height h1 of the face tooth of the gauge; measuring the axial height H3 at the outer circle of the tooth top after the face tooth top of the workpiece is fine-turned; calculating the theoretical center height h3 of the face tooth of the workpiece; after the face tooth of the workpiece is processed, meshing the gauge with the workpiece, measuring the distance H2 between the bottom surface of the gauge and the reference surface of the workpiece; calculating the actual center height h3' of the face tooth of the workpiece, comparing the actual value h3' of the center height of the tooth with the theoretical center height h3, and if it is within the allowable tolerance range, it is considered that the tooth height meets the requirements, and the actual center height h3' is the face tooth tooth height. This method uses the geometric relationship after the workpiece and the gauge are meshed, the relationship between the associated dimensions of the workpiece and the parameters of the face tooth, to obtain the actual tooth height of the face tooth on the workpiece. It can be seen from this that although this detection method can detect the relationship between the associated dimensions of the workpiece and the parameters of the end face teeth, this situation is detected in the case of straight tooth end face teeth. Since the VGR rack has different gear ratios at the center and both ends of the rack, this method cannot detect the symmetry on both sides of the VGR rack tooth area. Utility Model Content

[0007] Purpose of the utility model: In order to solve the deficiencies of the prior art, the utility model provides a gauge for detecting the symmetry of the two sides of the VGR rack tooth area. The gauge is simple to operate, quick to use, and can efficiently perform rapid screening of mass-produced products.

[0008] Technical solution: In order to achieve the above objectives, the utility model discloses a checking fixture for detecting the symmetry of the tooth area on both sides of a VGR rack, which comprises: a base plate, an axial support mechanism fixed on the base plate, a radial limiting mechanism for radially limiting the workpiece placed on the axial support mechanism, a detection mechanism for checking the symmetry of the workpiece, and a switch installed on the base plate and used to power on and off the radial limiting mechanism and the detection mechanism.

[0009] As a further preferred embodiment of the utility model, the axial support mechanism includes: a workpiece support block, an axial stopper and an elastic gear seat fixed to the base plate by a detachable connection, the workpiece is placed on multiple workpiece support blocks, the elastic gear seat is located below the workpiece and is stuck in the tooth groove on the workpiece, and the axial stopper is located on one side of the workpiece support block and is used to abut against the end of the workpiece.

[0010] As a further preferred embodiment of the present invention, the workpiece support block, the axial stopper and the elastic gear seat are located on the same straight line.

[0011] As a further preference of the utility model, the elastic tooth seat includes a tooth seat fixing block fixed to the base plate by a threaded connection, a fixing bolt passed through the tooth seat fixing block, a spring sleeved on the fixing bolt, and a center tooth seat fixedly connected to the end of the fixing bolt, one end of the center tooth seat is connected to the spring, and the other end of the center tooth seat is clamped in the tooth groove on the workpiece.

[0012] As a further preferred embodiment of the present invention, a gap of 2 mm is provided between the lower end of the fixing bolt and the bottom of the gear holder fixing block. The gap is the distance of linear movement of the center gear holder, and the lower end of the fixing bolt is stuck in the T-slot of the gear holder fixing block;

[0013] When the tooth groove of the workpiece is stuck on the central tooth-shaped seat, the central tooth-shaped seat drives the fixing bolt to press downward, and the central tooth-shaped seat compresses the spring, thereby driving the fixing bolt to move downward to overcome the spring force of the spring;

[0014] When the tooth groove of the workpiece is separated from the center tooth seat, the center tooth seat drives the fixing bolt to move upward under the spring force of the spring, and the lower end of the fixing bolt is stuck in the T-slot of the tooth seat fixing block to limit the upward movement limit of the center tooth seat.

[0015] As a further preferred embodiment of the present invention, the radial limiting mechanism includes: a pressure block cylinder support column, a cylinder A, a cylinder B and a pressure head. The bottom of the pressure block cylinder support column is vertically fixed on the base plate. Cylinder A and cylinder B are respectively installed on the upper part of the two pressure block cylinder support columns. Pressure heads are respectively provided at the output ends of cylinder A and cylinder B. The positions of the pressure heads and the radial surface of the workpiece are relative.

[0016] As a further preferred embodiment of the present invention, the cylinder A and the cylinder B are connected to the pneumatic switch A and the pneumatic switch B respectively.

[0017] As a further preferred embodiment of the present invention, the detection mechanism comprises: a detection plate, a detection head A, a detection head B, a dial indicator, a dial indicator bracket, a buffer bracket, a buffer, a cylindrical cylinder and a cylinder bracket;

[0018] The buffer bracket for placing the buffer is fixed on the bottom plate by threaded connection. The detection head A and the detection head B are installed on the guide rail vertically arranged with the workpiece. The detection heads A and B that move linearly on the guide rail are opposite to each other at one end. The other ends of the detection heads A and B are respectively connected to the output ends of the cylindrical cylinder. The cylindrical cylinder is clamped on the cylinder brackets at both ends of the guide rail. The detection heads A and B are respectively provided with detection plates, which are against the output ends of the dial gauge fixed on the dial gauge bracket. The buffer is installed between the dial gauge and the workpiece to protect the dial gauge to prevent the dial gauge from being hit quickly by the detection heads A and B.

[0019] Since it is an existing technology that the cylindrical cylinder controls the linear movement of the detection head A and the detection head B on the guide rail, this technical feature has been widely used in the existing technology, such as remote control moving track doors, such as electric control car doors, etc., and this technical feature will not be described in detail here.

[0020] As a further preferred embodiment of the present invention, the guide rails of the detection head A and the detection head B are matched in the following manner: a linear rail slider, a T-slot, or a dovetail groove.

[0021] As a further preferred embodiment of the present invention, the two cylindrical cylinders connected to the detection head A and the detection head B are connected to the pneumatic switch C and the pneumatic switch D respectively.

[0022] Beneficial effects: Compared with the prior art, the inspection fixture for detecting the symmetry of the tooth area on both sides of the VGR rack described in the utility model has few inspection fixture components, a short assembly process and low cost. Compared with three-coordinate and profiler precision inspection fixtures, it has low professional requirements for operators and is simple to operate. It can efficiently and quickly screen mass-produced products. The inspection fixture has low cost and is suitable for mass production and application promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the utility model after the workpiece is installed;

[0024] Figure 2 This is a top view of the utility model after the workpiece is installed;

[0025] Figure 3 It is a partial enlarged view of the elastic gear seat;

[0026] Figure 4 It is the main view of the workpiece;

[0027] Figure 5 This is a full left view of the workpiece. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] As shown in the accompanying drawings, the utility model is a kind of inspection fixture for detecting the symmetry of the tooth area on both sides of the VGR rack, which includes: a base plate 2, a detection plate 3, a workpiece support block 4, an axial stopper 5, a pressure block cylinder support column 6, a cylinder A71, a cylinder B72, a pressure head 8, a detection head A91, a detection head B92, a dial indicator 10, a dial indicator bracket 11, a buffer bracket 12, a buffer 13, a pneumatic switch A141, a pneumatic switch B142, a pneumatic switch C143, a pneumatic switch D144, an elastic gear seat 15, a cylindrical cylinder 16, and a cylinder bracket 17.

[0030] The workpiece support block 4, axial stop block 5 and elastic gear seat 15 located on the same straight line are respectively fixed on the base plate 2 by detachable connection. The workpiece 1 is placed on multiple workpiece support blocks 4. The elastic gear seat 15 is located below the workpiece 1 and is stuck in the tooth groove on the workpiece 1. The axial stop block 5 is located on one side of the workpiece support block 4 and is used to abut against the end of the workpiece 1.

[0031] The bottom of the briquetting cylinder support column 6 is vertically fixed on the base plate 2, and the upper parts of the two briquetting cylinder support columns 6 are respectively installed with cylinder A71 and cylinder B72. The output ends of cylinder A71 and cylinder B72 are respectively provided with pressure heads 8. The positions of the pressure heads 8 and the radial surface of the workpiece 1 are opposite. Cylinder A71 and cylinder B72 are respectively connected to pneumatic switches A141 and pneumatic switches B142.

[0032] The buffer bracket 12 for placing the buffer 13 is fixed on the base plate 2 by means of a threaded connection. The detection head A91 and the detection head B92 are cooperatively installed on a guide rail vertically arranged to the workpiece 1. One ends of the detection head A91 and the detection head B92 moving linearly on the guide rail are opposite to each other, and the other ends of the detection head A91 and the detection head B92 are respectively fixedly connected to the output ends of the cylindrical cylinder 16. The cylindrical cylinder 16 is clamped on the cylinder bracket 17 located at both ends of the guide rail. The detection head A91 and the detection head B92 are respectively provided with a detection plate 3, and the detection plate 3 is offset against the output end of the dial indicator 10 fixed on the dial indicator bracket 11. The two cylindrical cylinders 16 connected to the detection head A91 and the detection head B92 are respectively connected to the pneumatic switch C143 and the pneumatic switch D144.

[0033] Example

[0034] Place the workpiece 1 on the workpiece support block 4, with the left end of the workpiece 1 close to the axial stopper 5. At this time, the tooth groove of the workpiece 1 is stuck on the central tooth-shaped seat 151 on the elastic tooth seat 15. Start the pneumatic switch A141 and the pneumatic switch B142, and the pressure head 8 connected to the cylinder A71 and the cylinder B72 presses on the workpiece 1, so that the workpiece 1 is fixed;

[0035] Start the pneumatic switch C143 and the pneumatic switch D144. The detection heads A91 and B92 connected to the cylindrical cylinder 16 move on the guide rails and slowly approach the workpiece 1 under the push of the cylindrical cylinder 16. The detection heads A91 and B92 are respectively provided with detection plates 3 that abut against the retractable detection part at the end of the dial indicator 10. The movement of the detection heads A91 and B92 will drive the pointer of the dial indicator 10 to rotate. When the detection heads A91 and B92 contact the workpiece 1, the pointer of the dial indicator 10 stops rotating.

[0036] When the pointer of dial indicator 10 rotates to within the qualified line range, the product is judged to be qualified. The value can also be read by the number of grids rotated by the pointer of dial indicator.

[0037] The above implementation is only to illustrate the technical concept and features of the utility model, and its purpose is to enable technicians familiar with the technical field to understand the content of the utility model and implement it accordingly, and it cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area, characterized in that: It includes: A base plate (2), an axial support mechanism fixedly mounted on the base plate (2), a radial limiting mechanism for radially limiting a workpiece (1) placed on the axial support mechanism, a detection mechanism for performing symmetry inspection on the workpiece (1), and a switch mounted on the base plate (2) and used to energize and deenergize the radial limiting mechanism and the detection mechanism.

2. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 1, characterized in that: The axial support mechanism comprises: a workpiece support block (4), an axial stopper (5) and an elastic tooth seat (15) fixed on a base plate (2) in a detachable manner; the workpiece (1) is placed on a plurality of workpiece support blocks (4); the elastic tooth seat (15) is located below the workpiece (1) and is clamped in a tooth groove on the workpiece (1); and the axial stopper (5) is located on one side of the workpiece support block (4) and is used to abut against the end of the workpiece (1).

3. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 2, characterized in that: The workpiece support block (4), the axial stopper (5) and the elastic gear seat (15) are located on the same straight line.

4. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 2, characterized in that: The elastic tooth seat (15) comprises a tooth seat fixing block (154) fixed on the base plate (2) by means of a threaded connection, a fixing bolt (153) passing through the tooth seat fixing block (154), a spring (152) sleeved on the fixing bolt (153), and a central tooth seat (151) fixedly connected to the end of the fixing bolt (153), one end of the central tooth seat (151) is connected to the spring, and the other end of the central tooth seat (151) is clamped in a tooth groove on the workpiece (1).

5. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 4, characterized in that: A gap is provided between the lower end of the fixing bolt (153) and the bottom of the gear seat fixing block (154).

6. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 1, characterized in that: The radial limiting mechanism comprises: a pressure block cylinder support column (6), a cylinder A (71), a cylinder B (72) and a pressure head (8), wherein the bottom of the pressure block cylinder support column (6) is vertically fixed on the bottom plate (2), the upper parts of the two pressure block cylinder support columns (6) are respectively installed with cylinders A (71) and cylinders B (72), and the output ends of cylinders A (71) and cylinders B (72) are respectively provided with pressure heads (8), and the positions of the pressure heads (8) and the radial surface of the workpiece (1) are relative.

7. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 6, characterized in that: The air cylinder A (71) and the air cylinder B (72) are connected to the pneumatic switch A (141) and the pneumatic switch B (142) respectively.

8. The inspection tool for inspecting the symmetry of the teeth of a VGR rack according to claim 1, characterized in that: The detection mechanism comprises: a detection plate (3), a detection head A (91), a detection head B (92), a dial indicator (10), a dial indicator bracket (11), a buffer bracket (12), a buffer (13), a cylindrical cylinder (16) and a cylinder bracket (17); A buffer bracket (12) for placing a buffer (13) is fixed on the base plate (2) by means of a threaded connection. The detection head A (91) and the detection head B (92) are mounted on a guide rail vertically arranged on the workpiece (1). One end of the detection head A (91) and the detection head B (92) moving linearly on the guide rail are opposite to each other. The other ends of the detection head A (91) and the detection head B (92) are respectively fixedly connected to the output end of the cylindrical cylinder (16). The cylindrical cylinder (16) is clamped on the cylinder bracket (17) located at both ends of the guide rail. The detection head A (91) and the detection head B (92) are respectively provided with a detection plate (3). The detection plate (3) is against the output end of the dial gauge (10) fixed on the dial gauge bracket (11).

9. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 8, characterized in that: The guide rails of the detection head A (91) and the detection head B (92) are connected in the following ways: linear rail slider connection, T-slot connection or dovetail groove connection.

10. A test fixture for detecting the symmetry of the two sides of the VGR rack tooth area according to claim 8, characterized in that: Two cylindrical cylinders (16) connected to the detection head A (91) and the detection head B (92) are connected to the pneumatic switch C (143) and the pneumatic switch D (144) respectively.

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