A method of designing and manufacturing a hard scraping drawbar for post-heat use

Abstract

The application discloses a design and manufacturing method of a hard broach for hot post-service, and comprises the following steps: (1) collecting machining requirements and machining data of a machined part; (2) designing the structure of the hard broach: the hard broach is designed as a hollow hard broach, the hollow hard broach comprises a broach guiding section, a broach rough cutting section and a broach fine cutting section; guiding spline teeth and guiding circular hole teeth are sequentially arranged on the broach guiding section, a plurality of rough cutting spline tooth sections and rough cutting circular hole tooth sections are alternately arranged on the broach rough cutting section, and a plurality of fine cutting spline tooth sections and fine cutting circular hole tooth sections are alternately arranged on the broach fine cutting section; (3) designing the size parameters of the hard broach; (4) designing and manufacturing a test broach of the hard broach; (5) testing the hard broach; (6) modifying the design and manufacturing of the hard broach; and (7) verifying the design of the hard broach. The application optimizes the existing design method of the hard broach and improves the broaching precision of the internal spline gear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of broach design, in particular to a design and manufacturing method of a hard scraping broach used after heat treatment. BACKGROUND

[0002] The spline broach is a kind of broach used for machining internal spline of a part. The typical spline broach is an internal spline gear broach.

[0003] With the increasing requirements for automobile driving, the requirements for comfort and controllability are higher and higher, and the precision of each transmission matching is higher and higher. The precision of the related transmission gear is currently required to be 5-6 level. The internal spline gear is deformed and the surface is rough after heat treatment, and the precision is 9-12 level, which cannot meet the high-precision transmission requirements. Some manufacturers will reduce the tooth rise of high-speed steel broach and increase the hardness of the tooth surface to process the workpiece again (which becomes heat treatment machining), and the precision is 7-9 level. The machined workpiece often has problems such as accumulated spline tooth and large runout, and the process qualification rate is low, which seriously affects the machining quality. Therefore, it is urgent to develop a design technology of high-precision and multi-functional hard scraping broach to meet the requirements of modern machining technology. SUMMARY

[0004] In order to solve the above problems, the present application provides a design and manufacturing method of a hard scraping broach used after heat treatment, which aims to optimize the design method of the existing hard scraping broach to improve the broaching precision of the internal spline gear. The specific technical scheme is as follows:

[0005] A design and manufacturing method of a hard scraping broach used after heat treatment, comprising the following steps:

[0006] (1) Collecting the machining requirements of the internal spline gear to be machined;

[0007] (2) Structure design of the hard scraping broach; the hard scraping broach is designed as a hollow hard scraping broach, which comprises a broach guide section, a broach rough cutting section and a broach fine cutting section connected integrally in sequence; wherein the broach guide section is provided with guide spline teeth and guide circular hole teeth in sequence, the broach rough cutting section is alternately provided with a plurality of rough cutting spline tooth sections and rough cutting circular hole tooth sections, and the broach fine cutting section is alternately provided with a plurality of fine cutting spline tooth sections and fine cutting circular hole tooth sections;

[0008] (3) Size parameter design of the hard scraping broach: according to the design structure and broach design standard of the hard scraping broach, the size parameter design of the hard scraping broach is carried out;

[0009] (4) Design and manufacture of the hard scraping broach test broach: based on the data of the structure design and size parameter design of the hard scraping broach, the hard scraping broach test broach for broaching test is designed and manufactured.

[0010] (5) Trial broaching with hard broach: using the trial broach to broach the internal spline gear after the broaching and heat treatment, and checking the precision of the broached internal spline gear;

[0011] (6) Modification design and manufacture of hard broach: according to the trial broaching result of the trial broach, modifying and designing the size parameters of the hard broach, and designing and manufacturing the modified hard broach;

[0012] (7) Design verification of hard broach: using the modified hard broach to broach the internal spline gear after the broaching and heat treatment, and checking the precision of the broached internal spline gear; if the checking is qualified, the size parameters of the modified hard broach are taken as the size parameters of the hard broach for formal machining; if the checking is unqualified, repeating steps (6) to (7) until the checking is qualified.

[0013] The machining requirements and the contents of the machining data collection of the machined part in the step (1) include: determining the tooth thickness, the major diameter and the minor diameter of the internal spline gear, determining the module, the pressure angle, the number of teeth and the machining length of the internal spline gear, determining the heat-treated blank data of the internal spline gear, determining the finished part data of the internal spline gear, and determining the machining length of the internal spline gear; wherein the heat-treated blank data of the internal spline gear includes the major diameter Drq, the minor diameter drq and the tooth thickness Srq, the finished part data of the internal spline gear includes the major diameter Dcp, the minor diameter dcp and the tooth thickness Scp, and the machining length of the internal spline gear is L.

[0014] In the size parameter design of the hard broach in the step (3), the following size parameters of the hard broach are set: the outer diameter of the guide spline tooth is Ddx=Drq-δ; the outer diameter of the guide circular hole tooth is ddx=drg-δ; and the tooth thickness of the guide spline tooth is Sdx=Srq-κ; wherein δ is the guide gap of the outer diameter of the guide spline tooth and the outer diameter of the guide circular hole tooth, and κ is the guide gap of the tooth thickness of the guide spline tooth.

[0015] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount.

[0016] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount.

[0017] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the tooth pitch of the hard scraping broach is designed as The rake angle is γ=-15°, the tooth back angle is θ=50-60°, the outer circle rake angle is α=1-2°, and the chip space depth is The tooth top width is g=(0.35-0.40)*P, the groove bottom arc radius is R=0.2*Mn, and the tooth back arc radius is r=0.2*Mn; wherein K is the minimum chip space coefficient for ensuring smooth chip removal and avoiding iron chip jamming, and Mn is the workpiece normal modulus.

[0018] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the groove bottom diameter of the hard scraping broach is designed as Dr=ddx-2h; the inner hole diameter of the hard scraping broach is designed as Dk=Dr-Ks; wherein Ks is the tool wall thickness, and is greater than or equal to 3 mm to ensure tool strength; ddx is the circular hole tooth outer diameter, h is the chip space depth, Dr is the chip space bottom diameter, and enough chip space is ensured.

[0019] The method for designing and manufacturing the hard broach used after heat further sets the size parameters of the hard broach as follows: the width of the end face positioning key groove of the hard broach is Wk=Dk-Kr, and the groove depth is Wh=3-5mm; wherein Kr is a coefficient, and the value is 2-3mm.

[0020] As a further improvement of the present application, the minimum chip space coefficient is determined in the process of designing and manufacturing the hard broach test broach in step (4) through the following steps.

[0021] S1, a chip space real-time monitoring device is arranged on the hard broach test broach, which includes a layer of shape memory glue arranged at the bottom of the deepened chip groove based on the data of the structural design and size parameter design of the hard broach, and the thickness of the shape memory glue is just equal to the depth of the deepened part of the chip groove.

[0022] S2, the hard broach test broach with the shape memory glue is used to perform the hard broach test in step (5), after the test is completed, the damage deformation of the shape memory glue is detected to determine whether the chip groove depth meets the requirements, and the part with a small chip groove depth is corrected in the correction design and manufacturing process of the hard broach in step (6), so as to design and manufacture the corrected hard broach.

[0023] Preferably, the shape memory glue is eucommia ulmoides in a crystalline state at room temperature, which is coated on the bottom of the chip groove of the hard broach test broach through heating means, and is precisely machined to a thickness just equal to the depth of the deepened part of the chip groove after cooling to room temperature; and before the hard broach test in step (5), the shape memory glue is quickly heated to the softening point by using the glue online rapid heating device on the broaching machine, and then the hard broach test in step (5) is performed.

[0024] The glue online rapid heating device includes a pair of magnetic suction type half pipes movably arranged on the broaching machine and located at the periphery of the hard broach test broach, a semi-annular hot gas flow distribution cavity corresponding arranged on the outer circle of the magnetic suction type half pipe, hot gas flow distribution holes arranged on the semi-annular hot gas flow distribution cavity in a circumferential direction and connected with the inner holes of the pair of magnetic suction type half pipes, and a hot gas flow source connected with the semi-annular hot gas flow distribution cavity through a hose.

[0025] Preferably, a recess is formed between the magnetic attraction surfaces of the pair of magnetic attraction half pipes, and an elastic member is arranged in the recess, and the magnetic attraction point temperature of the pair of magnetic attraction half pipes is set to be higher than the softening point temperature of the shape memory glue by a temperature difference, when the hot air flowing into the pair of magnetic attraction half pipes heats the pair of magnetic attraction half pipes to be close to the magnetic attraction point temperature, the magnetic attraction between the pair of magnetic attraction half pipes rapidly decays, the elastic force of the elastic member pushes open the magnetic attraction surfaces of the pair of magnetic attraction half pipes, indicating that the softening point temperature of the shape memory glue has reached, reminding the broaching machine operator to immediately remove the pair of magnetic attraction half pipes, and then the trial broaching operation of the (5) hard scraping broach is completed before the shape memory glue reaches the crystallization temperature.

[0026] Preferably, the temperature difference is 10-20℃.

[0027] Preferably, the elastic member is composed of an adjusting gasket arranged at the bottom of the recess and a pagoda spring arranged above the adjusting gasket.

[0028] The beneficial effects of the present application are:

[0029] First, the design and manufacturing method of the hard scraping broach used after heating according to the deformation instability of the workpiece after heating, the size and precision of the tool guide teeth improve the state during broaching and the precision after broaching, the tooth consistency and straightness requirement is greatly improved, and the deflection in processing is eliminated or reduced.

[0030] Second, the design and manufacturing method of the hard scraping broach used after heating, according to the tooth thickness, large diameter, small diameter allowance of the workpiece after heating, determines the tooth rise of the rough and fine broaching spline teeth and the rough and fine broaching circular hole teeth, improves the tool life, stabilizes the machining precision, and reduces the workpiece deformation.

[0031] Third, the design and manufacturing method of the hard scraping broach used after heating, according to the relationship and calculation scheme between the tool material and structure parameters determined according to the material, structure characteristics and parameters of the workpiece and the material performance, structure characteristics and parameters of the machined workpiece, finally realizes the data and structure required for tool design.

[0032] Fourth, the design and manufacturing method of the hard scraping broach used after heating, aiming at the problem that it is difficult to design by experience in the conventional broach chip space design method, a chip space real-time monitoring device is specially arranged on the test broach of the hard scraping broach, the hard scraping broach can be designed and manufactured according to the data measured online by the chip space real-time monitoring device, thereby improving the accuracy of the design of the size parameters of the broach chip space, further improving the design quality of the hard scraping broach, thereby being beneficial to further improve the broaching precision of the internal spline gear, and also improving the service life of the hard scraping broach. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a flowchart of a method for designing and manufacturing a hard scraping broach for post-heat use according to the present application;

[0034] Figure 2 is a structural schematic diagram of a hard scraping broach;

[0035] Figure 3 is Figure 2 is a sectional view of the circular hole tooth and spline tooth of the hard scraping broach;

[0036] Figure 4 is an embodiment of a chip pocket involved in the method for designing and manufacturing a hard scraping broach for post-heat use according to the present application;

[0037] Figure 5 is a structural schematic diagram of a colloidal online rapid heating device.

[0038] In the figure: 1, broach guide section, 2, broach rough cutting section, 3, broach fine cutting section, 4, hard scraping broach test broach, 5, magnetic type half pipe, 6, semi-annular hot gas flow distribution cavity, 7, hot gas flow distribution hole, 8, hose, 9, sink, 10, elastic member, 11, adjusting gasket, 12, pagoda spring. DETAILED DESCRIPTION

[0039] The specific embodiments of the present application will be further described below in conjunction with the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0040] As Figures 1 to 5 shown is an embodiment of a method for designing and manufacturing a hard scraping broach for post-heat use according to the present application, comprising the following steps:

[0041] (1) Collecting the processing requirements of the internal spline gear to be processed;

[0042] (2) Structural design of the hard scraping broach; the hard scraping broach is designed as a hollow hard scraping broach, which comprises a broach guide section 1, a broach rough cutting section 2 and a broach fine cutting section 3 connected integrally in sequence; wherein the broach guide section 1 is provided with guide spline teeth and guide circular hole teeth in sequence, the broach rough cutting section 2 is provided with a plurality of rough cutting spline tooth sections and rough cutting circular hole tooth sections alternately in sequence, and the broach fine cutting section 3 is provided with a plurality of fine cutting spline tooth sections and fine cutting circular hole tooth sections alternately in sequence;

[0043] (3) Design of the size parameters of the hard scraping broach: according to the design structure of the hard scraping broach and the broach design standard, the size parameters of the hard scraping broach are designed;

[0044] (4) Design and manufacture of the hard-broach test broach: based on the data of the structural design and the size parameter design of the hard-broach, the hard-broach test broach 4 used for the broaching test is designed and manufactured;

[0045] (5) Hard-broaching test: using the hard-broach test broach, the internal spline gear after the broaching and heat treatment is tested, and the precision of the internal spline gear after the broaching test is detected;

[0046] (6) Correction design and manufacture of the hard-broach: according to the broaching test result of the hard-broach test broach, the size parameter of the hard-broach is corrected and designed, and the corrected hard-broach is designed and manufactured;

[0047] (7) Design verification of the hard-broach: using the corrected hard-broach, the internal spline gear after the broaching and heat treatment is broached, and the precision of the internal spline gear after the broaching is detected; if the detection is qualified, the size parameter of the corrected hard-broach is used as the size parameter of the hard-broach for formal machining; if the detection is unqualified, steps (6) to (7) are repeated until the detection is qualified.

[0048] The machining requirements and the contents of the machining data collection of the machined part in the step (1) include: determining the tooth thickness, the major diameter and the minor diameter of the internal spline gear, determining the module, the pressure angle, the number of teeth and the machining length of the internal spline gear, determining the hot post-blank data of the internal spline gear, determining the finished part data of the internal spline gear, and determining the machining length of the internal spline gear; wherein the hot post-blank data of the internal spline gear includes the major diameter Drq, the minor diameter drq and the tooth thickness Srq, the finished part data of the internal spline gear includes the major diameter Dcp, the minor diameter dcp and the tooth thickness Scp, and the machining length of the internal spline gear is L.

[0049] In the size parameter design of the hard-broach in the step (3), the following size parameters of the hard-broach are set: the guide spline tooth outer diameter is Ddx=Drq-δ; the guide circular hole tooth outer diameter is ddx=drg-δ; and the guide spline tooth thickness is Sdx=Srq-κ; wherein δ is the guide gap of the guide spline tooth outer diameter and the guide circular hole tooth outer diameter, and κ is the guide gap of the guide spline tooth thickness.

[0050] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount.

[0051] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount.

[0052] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount. The rake angle is γ=-15°, the tooth back angle is θ=50-60°, the outer circle rake angle is α=1-2°, and the chip space depth is The tooth top width is g=(0.35-0.40)*P, the groove bottom arc radius is R=0.2*Mn, and the tooth back arc radius is r=0.2*Mn; wherein K is the minimum chip space coefficient for ensuring smooth chip removal and avoiding iron chip jamming, and Mn is the workpiece normal modulus.

[0053] The design and manufacturing method of the hard scraping broach for post-heat use further sets the size parameters of the hard scraping broach as follows: the outer diameter of the first rough key tooth is Dcq1=Drq; the outer diameter of the first rough circular hole tooth is dcq1=drq; the tooth thickness of the first rough key tooth is Scq1=Srq; the outer diameter of the last rough key tooth is Dcqn=Dcp-Di; the outer diameter of the last rough circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough key tooth is Scqn=Scp-Si; the number of rough key teeth is NDcq=(Dcqn-Dcq1) / fr; the number of rough circular hole teeth is Ndcq=(dcqn-dcq1) / fr; wherein Di is the rough key tooth outer diameter fine-drawing reserved amount, di is the rough circular hole tooth fine-drawing reserved amount, Si is the rough key tooth thickness fine-drawing reserved amount, and fr is the rough key tooth and rough circular hole tooth tooth rise amount.

[0054] The method for designing and manufacturing a hard scraping broach for post-heat use of the application further sets the size parameters of the hard scraping broach as follows: the width of the end face positioning key groove of the hard scraping broach is Wk=Dk-Kr, and the groove depth is Wh=3-5mm; wherein Kr is a coefficient, and the value is 2-3mm.

[0055] As a further improvement of the application, the minimum chip space coefficient is determined in the process of designing and manufacturing the hard scraping broach test broach in step (4) through the following steps.

[0056] S1, a chip space real-time monitoring device is arranged on the hard scraping broach test broach, which includes a layer of shape memory glue arranged at the bottom of the deepened chip groove based on the data of the structural design and size parameter design of the hard scraping broach, and the thickness of the shape memory glue is exactly equal to the depth of the deepened part of the chip groove.

[0057] S2, the hard scraping broach test broach with the shape memory glue is used to perform the hard scraping broach test in step (5), after the test is completed, the damage and deformation of the shape memory glue is detected to determine whether the chip groove depth meets the requirements, and the part with a small chip groove depth is corrected in the correction design and manufacturing process of the hard scraping broach in step (6), and a corrected hard scraping broach is designed and manufactured.

[0058] Preferably, the shape memory glue is eucommia ulmoides in a crystalline state at room temperature, which is coated on the bottom of the chip groove of the hard scraping broach test broach through heating means, and is precisely machined to a thickness exactly equal to the depth of the deepened part of the chip groove after cooling to room temperature; and before the hard scraping broach test in step (5), an online rapid heating device for the glue is used on the broaching machine to rapidly heat the shape memory glue to the softening point before the hard scraping broach test in step (5).

[0059] The online rapid heating device for the glue includes a pair of magnetic suction type half pipes 5 movably arranged on the broaching machine and located outside the hard scraping broach test broach 4, a semi-annular hot gas flow distribution cavity 6 arranged on the outer circle of the magnetic suction type half pipe 5, hot gas flow distribution holes 7 arranged on the semi-annular hot gas flow distribution cavity 6 in a circumferential interval and connected with the inner holes of the pair of magnetic suction type half pipes 5, and a hot gas flow source connected with the semi-annular hot gas flow distribution cavity 6 through a hose 8.

[0060] Preferably, a recess 9 is formed between the magnetic attraction surfaces of the pair of magnetic attraction half-pipes 5, and an elastic member 10 is arranged in the recess 9. The magnetic attraction Curie point temperature of the pair of magnetic attraction half-pipes 5 is set to be higher than the softening point temperature of the shape memory glue by a temperature difference. When the hot air flowing into the pair of magnetic attraction half-pipes 5 heats the pair of magnetic attraction half-pipes 5 to a temperature close to the magnetic attraction Curie point temperature, the elastic force of the elastic member 10 pushes open the magnetic attraction surfaces of the pair of magnetic attraction half-pipes 5, indicating that the softening point temperature of the shape memory glue has been reached, and reminding the operator of the broaching machine to immediately remove the pair of magnetic attraction half-pipes 5, and then to complete the trial broaching operation of the (5) hard scraping broach before the shape memory glue crystallizes.

[0061] Preferably, the temperature difference is 10-20°C.

[0062] Preferably, the elastic member 10 is composed of an adjusting gasket 11 arranged at the bottom of the recess 9 and a pagoda spring 12 arranged above the adjusting gasket 11.

[0063] The above description is only the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the technical principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A method of designing and manufacturing a hard-bitten broach for post-thermal use, characterized by, It comprises the following steps: (1) collecting the processing requirements of the internal spline gear to be processed; (2) structural design of the hard scraping broach; the hard scraping broach is designed as a hollow hard scraping broach, which comprises a broach guide section, a broach rough cutting section and a broach fine cutting section connected integrally in sequence; wherein the broach guide section is provided with guide spline teeth and guide circular hole teeth in sequence; the broach rough cutting section is alternately provided with a plurality of rough cutting spline tooth sections and rough cutting circular hole tooth sections; the broach fine cutting section is alternately provided with a plurality of fine cutting spline tooth sections and fine cutting circular hole tooth sections; (3) size parameter design of the hard scraping broach; according to the design structure and broach design standard, the size parameter design of the hard scraping broach is carried out; (4) design and manufacture of the hard scraping broach test broach; the hard scraping broach test broach for the test of broaching is designed and manufactured according to the data of the structural design and size parameter design of the hard scraping broach; (5) test broaching of the hard scraping broach; the internal spline gear after broaching and heat treatment is tested by using the hard scraping broach test broach, and the precision of the tested internal spline gear is detected; (6) correction design and manufacture of the hard scraping broach; according to the test broaching result of the hard scraping broach test broach, the size parameter of the hard scraping broach is corrected and designed, and the corrected hard scraping broach is designed and manufactured; (7) design verification of the hard scraping broach; the internal spline gear after broaching and heat treatment is broached by using the corrected hard scraping broach, and the precision of the broached internal spline gear is detected; if the detection is qualified, the size parameter of the corrected hard scraping broach is taken as the size parameter of the hard scraping broach for formal processing; if the detection is unqualified, steps (6) to (7) are repeated until the detection is qualified; The content of step (1) includes determining the tooth thickness, major diameter and minor diameter of the internal spline gear, determining the modulus, pressure angle, tooth number and processing length of the internal spline gear, determining the heat after blank data of the internal spline gear, determining the finished part data of the internal spline gear, and determining the processing length of the internal spline gear; wherein the heat after blank data of the internal spline gear includes the major diameter Drq, the minor diameter drq and the tooth thickness Srq, the finished part data of the internal spline gear includes the major diameter Dcp, the minor diameter dcp and the tooth thickness Scp, and the processing length of the internal spline gear is L; In the size parameter design of the hard scraping broach in step (3), the following size parameters of the hard scraping broach are set: the outer diameter of the guide spline tooth is Ddx=Drq-δ; the outer diameter of the guide circular hole tooth is ddx=drg-δ; the tooth thickness of the guide spline tooth is Sdx=Srq-κ; wherein δ is the guide gap of the outer diameter of the guide spline tooth and the outer diameter of the guide circular hole tooth, and κ is the guide gap of the tooth thickness of the guide spline tooth. The size parameters of the hard scraping broach are set as follows: the outer diameter of the first rough cutting spline tooth is Dcq1=Drq; the outer diameter of the first rough cutting circular hole tooth is dcq1=drq; the tooth thickness of the first rough cutting spline tooth is Scq1=Srq; the outer diameter of the last rough cutting spline tooth is Dcqn=Dcp-Di; the outer diameter of the last rough cutting circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough cutting spline tooth is Scqn=Scp-Si; the number of the rough cutting spline tooth is NDcq=(Dcqn-Dcq1) / fr; the number of the rough cutting circular hole tooth is Ndcq=(dcqn-dcq1) / fr; wherein, Di is the rough cutting spline tooth outer diameter precision drawing reserve, di is the rough cutting circular hole tooth precision drawing reserve, Si is the rough cutting spline tooth thickness precision drawing reserve, and fr is the rough cutting spline tooth and the rough cutting circular hole tooth tooth rise amount; The size parameters of the hard scraping broach are set as follows: the outer diameter of the first rough cutting spline tooth is Dcq1=Drq; the outer diameter of the first rough cutting circular hole tooth is dcq1=drq; the tooth thickness of the first rough cutting spline tooth is Scq1=Srq; the outer diameter of the last rough cutting spline tooth is Dcqn=Dcp-Di; the outer diameter of the last rough cutting circular hole tooth is dcqn=dcp-di; the tooth thickness of the last rough cutting spline tooth is Scqn=Scp-Si; the number of the rough cutting spline tooth is NDcq=(Dcqn-Dcq1) / fr; the number of the rough cutting circular hole tooth is Ndcq=(dcqn-dcq1) / fr; wherein, Di is the rough cutting spline tooth outer diameter precision drawing reserve, di is the rough cutting circular hole tooth precision drawing reserve, Si is the rough cutting spline tooth thickness precision drawing reserve, and fr is the rough cutting spline tooth and the rough cutting circular hole tooth tooth rise amount; The size parameters of the hard scraping broach are as follows: the tooth pitch of the hard scraping broach is designed as P=1.5 , the rake angle is γ=-15°, the relief angle is θ=50-60°, the outside circle relief angle is α=1-2°, the chip space depth is h=1.13 , the tooth top width is g=(0.35-0.40)*P, the slot bottom arc radius is R=0.2*Mn, and the relief arc radius is r=0.2*Mn; wherein K is the minimum chip space coefficient for ensuring smooth chip removal and avoiding iron chip jamming, and Mn is the workpiece normal modulus. The size parameters of the hard scraping broach are set as follows: the hard scraping broach groove bottom diameter is designed as Dr=ddx-2h; the hard scraping broach inner hole diameter is designed as Dk=Dr-Ks; wherein, Ks is the tool wall thickness, and the value is ≥3mm, so as to ensure the tool strength; ddx is the circular hole tooth outer diameter, h is the chip space depth, and Dr is the chip space bottom diameter, so as to ensure sufficient chip space; The size parameters of the hard scraping broach are set as follows: the hard scraping broach end face positioning key groove width is Wk=Dk-Kr, and the groove depth is Wh=3~5mm; wherein, Kr is a coefficient, and the value is 2~3mm.

2. A method of designing and manufacturing a hot post-processed hard scraping broach according to claim 1, characterized in that, In the process of designing and manufacturing the hard scraping broach test broach in the step (4), the minimum chip space coefficient is determined through the following steps: S1, a chip space real-time monitoring device is arranged on the hard scraping broach test broach, the chip space real-time monitoring device includes data as a benchmark of the structure design and size parameter design of the hard scraping broach, the chip space depth is deepened, and then a layer of shape memory colloid is arranged at the groove bottom of the deepened chip space, and the thickness of the shape memory colloid is just equal to the depth of the deepened part of the chip space depth; S2, using a hard broach with a shape memory glue test broach to test the hard broach of step (5), after the test, detect the damage deformation of the shape memory glue, judge whether the chip groove depth meets the requirements, and correct the design and production process of the hard broach of step (6) to the part with small chip groove depth, and design and produce a corrected hard broach.

3. A method of designing and manufacturing a hot post-processed hard scraping broach according to claim 2, characterized in that, The shape memory glue adopts eucommia ulmoides rubber in a crystalline state at room temperature, which is coated to the groove bottom of the chip groove of the hard broach test broach through heating means, and after cooling to room temperature, it is finished to a thickness just equal to the depth of the deepened part of the chip groove; and before the test of the hard broach of step (5), the glue is quickly heated to the softening point by using an online quick heating device on the broaching machine, and then the test of the hard broach of step (5) is carried out.

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