A positioning tool for machining precise specific positional relationships of a sprocket

Abstract

The utility model relates to chain wheel machining technical field, especially a kind of positioning tool for the accurate specific position relationship of machining chain wheel. Including a base, central through slot is set in the middle part position of base, outer positioning group is set at the horizontal two sides on the base, inner positioning group is set at the longitudinal two sides on the base, in this structure, according to the diameter or the number of teeth of chain wheel selection outer positioning group positioning or inner positioning group positioning, first chain wheel is placed on base, then one chain tooth is moved to between two first positioning pin holes or two second positioning pin holes, then according to the size of chain wheel chain tooth selection corresponding specification two positioning pins and install on outer positioning pin hole group or inner positioning pin hole group, again, a limit pin is inserted into the long waist type positioning slot or waist type positioning hole and moves close to chain tooth to no gap, at this time, the chain tooth center line is aligned with the inner hole double key groove center of chain wheel, then the accurate and rapid positioning of the chain wheel can be realized, and subsequent processing is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of sprocket processing technology, and in particular to a positioning fixture for processing sprockets with precise and specific positional relationships. Background Technology

[0002] The technology for sprockets requires that the center of the double keyway in the inner bore be aligned with the center line of the sprocket teeth, with an alignment accuracy of less than 0.05mm, so that they can be interchanged during use. However, there are many types and specifications of sprockets, making positioning before machining very difficult. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a positioning fixture for machining the precise and specific positional relationship between sprocket teeth and keyways, which can achieve accurate and rapid position positioning.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a positioning fixture for processing precise and specific positional relationships of sprockets, wherein the inner hole of the sprocket is provided with a double keyway, and the double keyway consists of two keyways symmetrically arranged about the central axis of the sprocket. Its innovation lies in: including... A base, the base comprising a horizontally arranged rectangular structural plate; A central through slot, the central through slot being a symmetrical structure, is opened through the middle of the base, and the central through slot has a transverse axis of symmetry and a longitudinal axis of symmetry. An external positioning assembly is provided on both sides of the base, including an external positioning pin hole assembly and an elongated positioning groove, for machining keyways on sprockets with larger diameters; The external positioning pin hole group is set on the base on the lateral side of the central through groove, including two adjacent first positioning pin holes, and the perpendicular bisector of the line connecting the centers of the two first positioning pin holes is collinear with the lateral axis of symmetry of the central through groove, and there is space between the two first positioning pin holes to accommodate a chain tooth extending in. The elongated positioning groove is provided on the other side of the central through groove on the base, and the elongated positioning groove is arranged horizontally, and the axis of symmetry of the elongated positioning groove is collinear with the horizontal axis of symmetry of the central through groove. An inner positioning group is provided on both longitudinal sides of the base, including an inner positioning pin hole group and a waist-shaped positioning hole, for machining keyways on sprockets with smaller diameters; The inner positioning pin hole group is set on the longitudinal side of the central through groove on the base, including two adjacent second positioning pin holes, and the perpendicular bisector of the line connecting the centers of the two second positioning pin holes is collinear with the longitudinal axis of symmetry of the central through groove, and there is also space between the two second positioning pin holes to accommodate a chain tooth to extend in. The waist-shaped positioning hole is longitudinally arranged on the base on the other side of the central through groove, and the longitudinal axis of symmetry of the waist-shaped positioning hole is collinear with the longitudinal axis of symmetry of the central through groove. Furthermore, the distance between the inner positioning group and the transverse axis of symmetry of the central through groove is less than the distance between the outer positioning group and the longitudinal axis of symmetry of the central through groove.

[0005] Furthermore, the base is also provided with multiple lifting screw holes, which can be used to install the base on the workbench by bolts through the lifting screw holes.

[0006] Furthermore, it also includes locating pins, of which there are two, and are respectively disposed on the outer locating pin hole group or the inner locating pin hole group.

[0007] Furthermore, it also includes a limiting pin, which is disposed in the waist-shaped positioning hole or the elongated waist-shaped positioning groove, and is used to cooperate with the positioning pin to realize the positioning and installation of the sprocket.

[0008] Furthermore, the positioning pin is vertically arranged and includes a bottom connecting section and a top limiting section arranged coaxially. The outer diameter and height of the top limiting section are selected according to the specifications of the sprocket teeth. Positioning pins with different outer diameters of the top limiting section can be selected according to the size of the sprocket, thereby realizing rapid positioning of sprockets of different sizes, which is highly practical.

[0009] The advantages of this utility model are: 1. In this structure, the sprocket is positioned using either an external or internal positioning group, depending on its diameter or number of teeth. First, the sprocket is placed flat on the base. Then, one chain tooth is moved between the two first positioning pin holes or the two second positioning pin holes. Next, two positioning pins of the appropriate specifications are selected according to the size of the sprocket teeth and installed on the external or internal positioning pin hole group. Then, a limiting pin is inserted into the elongated positioning groove or waist-shaped positioning hole and moved to fit snugly against the chain tooth until there is no gap. At this time, the center line of the chain tooth is aligned with the center of the double keyway in the inner hole of the sprocket, thus achieving precise and rapid positioning of the sprocket, which facilitates subsequent processing.

[0010] 2. In this structure, by selecting locating pins of different sizes according to the actual dimensions of the sprocket, rapid positioning of sprockets with different numbers of teeth or diameters can be achieved. The positioning accuracy is high and the application range is wide. Attached Figure Description

[0011] Figure 1 This is a top view of the present invention.

[0012] Figure 2 This is a cross-sectional view of the sprocket after it has been positioned and installed in this utility model.

[0013] Figure 3 This is a schematic diagram of the large-diameter sprocket installation structure of this utility model.

[0014] Figure 4 This is a schematic diagram of the small-diameter sprocket installation structure of this utility model. Detailed Implementation

[0015] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0016] like Figure 1-4 The positioning fixture shown is used to process the precise specific positional relationship between the chain teeth and keyway of a sprocket 4, and includes a base 1, two positioning pins 2 and a limiting pin 3.

[0017] The inner hole of sprocket 4 is provided with a double keyway, and the double keyway consists of two keyways symmetrically arranged about the central axis of sprocket 4.

[0018] The base 1 includes a horizontally arranged rectangular structural plate 11, a central through groove 12 is opened in the middle of the base 1, an outer positioning group 13 is arranged on both sides of the horizontal direction of the base 1, and an inner positioning group 14 is arranged on both sides of the vertical direction of the base 1.

[0019] Four lifting screw holes 15 are provided on the upper side of the base 1, and the base 1 can be horizontally installed on the workbench by using bolts through the lifting screw holes 15.

[0020] The central through groove 12 has a symmetrical structure, and the structure of the central through groove 12 is the same as the inner hole and double keyway structure of the sprocket 4. It includes a first longitudinal section, a first upper transverse section, an upper arc-shaped section, a second upper transverse section, a second longitudinal section, a second lower transverse section, a lower arc-shaped section, and a first lower transverse section connected in sequence. The first lower transverse section is connected to the first longitudinal section, and the first longitudinal section, the first upper transverse section, and the first lower transverse section form a first keyway hole. The second upper transverse section, the second longitudinal section, and the second lower transverse section form a second keyway hole. The central through groove 12 has a transverse axis of symmetry 16 and a longitudinal axis of symmetry 17.

[0021] The external positioning assembly 13 includes an external positioning pin hole assembly and an elongated positioning groove 132, which can be used to process keyways on sprockets 4 with larger diameters.

[0022] The outer positioning pin hole group is set on the base 1 on one side of the central through groove 12, including two adjacent first positioning pin holes 131, and the perpendicular line of the line connecting the centers of the two first positioning pin holes 131 is collinear with the horizontal axis of symmetry 16 of the central through groove 12, and there is space between the two first positioning pin holes 131 to accommodate a chain tooth to extend in.

[0023] An elongated positioning groove 132 is provided on the other side of the central through groove 12 on the base 1. The elongated positioning groove 132 is arranged horizontally, and the axis of symmetry of the elongated positioning groove 132 is collinear with the horizontal axis of symmetry 16 of the central through groove 12.

[0024] The inner positioning group 14 includes an inner positioning pin hole group and a waist-shaped positioning hole 142, which can be used to machine the keyway of the sprocket 4 with a smaller diameter.

[0025] The inner positioning pin hole group is set on the longitudinal side of the central through groove 12 on the base 1, including two adjacent second positioning pin holes 141, and the perpendicular bisector of the line connecting the centers of the two second positioning pin holes 141 is collinear with the longitudinal axis of symmetry 17 of the central through groove 12, and there is also space between the two second positioning pin holes 141 to accommodate a chain tooth extending in.

[0026] The waist-shaped positioning hole 142 is longitudinally arranged on the base 1 on the other side of the central through groove 12, and the longitudinal axis of symmetry 17 of the waist-shaped positioning hole 142 is collinear with the longitudinal axis of symmetry 17 of the central through groove 12.

[0027] Furthermore, the distance between the inner positioning group 14 and the transverse axis of symmetry 16 of the central through groove is less than the distance between the outer positioning group 13 and the longitudinal axis of symmetry 17 of the central through groove.

[0028] The two locating pins 2 are respectively set on the outer locating pin hole group or the inner locating pin hole group.

[0029] The positioning pin 2 is vertically set and includes a bottom connecting section and a top limiting section coaxially set. The bottom connecting section is set in the first positioning pin hole 131 or the second positioning pin hole 141. The top limiting section extends upward to the two sides of the chain teeth. The outer diameter and length of the top limiting section are selected according to the specifications of the sprocket 4 teeth. The positioning pin 2 with the corresponding outer diameter and height of the top limiting section can be selected according to the size of the sprocket 4 teeth, so as to realize the rapid positioning of sprockets 4 of different sizes, which is highly practical.

[0030] The limiting pin 3 is set in the waist-shaped positioning hole 142 or the long waist-shaped positioning groove 132, and the structure of the limiting pin 3 is the same as that of the positioning pin 2.

[0031] The working principle of this patent: In this structure, the outer positioning group 13 or the inner positioning group 14 is selected for positioning based on the diameter or number of teeth of the sprocket 4, such as... Figure 3The positioning and installation of the larger diameter sprocket 4 shown is as follows: First, place the sprocket 4 flat on the base 1. Then, move one chain tooth between the two first positioning pin holes 131. Next, select two positioning pins 2 of the appropriate specifications according to the size of the chain tooth of the sprocket 4 and install them on the outer positioning pin hole group or the inner positioning pin hole group. Then, insert a limit pin 3 of the appropriate specifications into the elongated positioning groove 132 and move it to fit the chain tooth until there is no gap. At this time, the center line of the chain tooth is aligned with the center of the double keyway in the inner hole of the sprocket 4, so that the sprocket 4 can be accurately and quickly positioned and the center position of the keyway can be found. Then, the two sides of the symmetrical keyway are wire cut.

[0032] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A positioning fixture for machining precise and specific positional relationships of a sprocket, wherein the inner bore of the sprocket is provided with a double keyway, and the double keyways are two keyways symmetrically arranged about the central axis of the sprocket, characterized in that: include A base, the base comprising a horizontally arranged rectangular structural plate; A central through slot, the central through slot being a symmetrical structure, is opened through the middle of the base, and the central through slot has a transverse axis of symmetry and a longitudinal axis of symmetry. An external positioning assembly is provided on both sides of the base, including an external positioning pin hole assembly and an elongated positioning groove. The external positioning pin hole group is set on the base on the lateral side of the central through groove, including two adjacent first positioning pin holes, and the perpendicular bisector of the line connecting the centers of the two first positioning pin holes is collinear with the lateral axis of symmetry of the central through groove, and there is space between the two first positioning pin holes to accommodate a chain tooth extending in. The elongated positioning groove is provided on the other side of the central through groove on the base, and the elongated positioning groove is arranged horizontally, and the axis of symmetry of the elongated positioning groove is collinear with the horizontal axis of symmetry of the central through groove. An inner positioning group is provided on both longitudinal sides of the base, including an inner positioning pin hole group and a waist-shaped positioning hole; The inner positioning pin hole group is set on the longitudinal side of the central through groove on the base, including two adjacent second positioning pin holes, and the perpendicular bisector of the line connecting the centers of the two second positioning pin holes is collinear with the longitudinal axis of symmetry of the central through groove, and there is also space between the two second positioning pin holes to accommodate a chain tooth to extend in. The waist-shaped positioning hole is longitudinally arranged on the base on the other side of the central through groove, and the longitudinal axis of symmetry of the waist-shaped positioning hole is collinear with the longitudinal axis of symmetry of the central through groove. Furthermore, the distance between the inner positioning group and the transverse axis of symmetry of the central through groove is less than the distance between the outer positioning group and the longitudinal axis of symmetry of the central through groove.

2. The positioning fixture for machining precise specific positional relationships of sprockets according to claim 1, characterized in that: The base is also provided with multiple lifting screw holes.

3. The positioning fixture for machining precise specific positional relationships of sprockets according to claim 1, characterized in that: It also includes locating pins, of which there are two, and are respectively disposed on the outer locating pin hole group or the inner locating pin hole group.

4. A positioning fixture for machining precise specific positional relationships of sprockets according to claim 1, characterized in that: It also includes a limiting pin, which is disposed in the waist-shaped positioning hole or the elongated waist-shaped positioning groove.

5. A positioning fixture for machining precise specific positional relationships of sprockets according to claim 3, characterized in that: The positioning pin is vertically arranged and includes a bottom connecting section and a top limiting section arranged coaxially. The outer diameter and height of the top limiting section are selected according to the specifications of the sprocket teeth.

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