A numerical control machining method for a spiral locking tooth surface of a locking mechanism

Abstract

The application discloses a numerical control machining method for a spiral locking tooth surface of a locking mechanism. The method is processed by a numerical control shaving machine tool, utilizes a point on a cutting edge and a tooth surface cutting mode, sets locking tooth angle positions and a pitch, and uses a special shaving cutter on the numerical control shaving machine tool to repeatedly cut in and out along the Z direction of the machine tool multiple times. All locking tooth surfaces are processed at one time, the start position of each spiral line of the tooth surface does not need to be determined multiple times, mechanical transmission gap conditions caused by repeated alignment are eliminated, and the size of the locking tooth is stable and controllable. The method significantly reduces processing time and cost, and improves batch production efficiency of the locking mechanism.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical processing, and particularly relates to a spiral locking tooth surface numerical control processing method of a locking mechanism. BACKGROUND

[0002] Reference Figures 1-2 The locking mechanism is a key component of a gun, and the spiral locking tooth surface structure of the locking mechanism is special. The distance between the locking tooth surface and the end surface of the locking mechanism on the center line of the locking tooth is usually required to be about 0.05 mm in precision, and the consistency precision of the distance between the plurality of tooth surfaces and the cross section of the locking mechanism is required to be within 0.04 mm, and the surface roughness is usually required to be above Ra1.6. The spiral locking tooth surface is difficult to process, and the processing process is complicated.

[0003] In the existing processing, the locking tooth surface is approximated as a multi-thread internal thread, and is processed on an ordinary lathe, that is, each tooth surface is a spiral line, and each spiral line has a fixed starting point on the locking mechanism, and the thread length is only about 0.5 mm. After the processing of one tooth surface is completed by using the forward and reverse turning method, the part needs to be clamped and aligned again, the tool setting value is calculated, the tool is fed and turned, and the operation is repeated.

[0004] The above processing method has the following problems: 1. When each locking tooth is processed, the starting point of each spiral line must be correctly found again, and all mechanical transmission clearances need to be excluded each time the tool is fed; 2. The tool is difficult to change in the middle, the cutting resistance is large, the tool wears quickly, the processing size error and tooth surface shape error are difficult to avoid, and the batch consistency is unstable; 3. In actual processing, the forward and reverse turning and the feeding and turning are performed about one thousand times, the labor intensity is large, the operator is easy to be tired, and the production efficiency is low; and the angle of rotation of the main shaft of the machine tool needs to be strictly controlled, the adjacent locking tooth cannot be scratched, the skill level and reaction speed of the operator are required to be high, and the operator must operate with high concentration for a long time. Therefore, the existing processing method is difficult to meet the batch production requirements of the locking mechanism. SUMMARY

[0005] In order to solve the problems that the starting point position needs to be determined many times in the processing of the locking tooth surface of the existing locking mechanism, the processing error is large, and the batch production efficiency is low, the present application provides a spiral locking tooth surface numerical control processing method of a locking mechanism.

[0006] The technical scheme adopted by the present application is as follows: a spiral locking tooth surface numerical control processing method of a locking mechanism, comprising the following steps:

[0007] Step 1, clamping the part, installing the center frame, and controlling the round runout;

[0008] Step 2, tool setting;

[0009] Step 2.1, the tool is clamped and aligned, the tool body of the special tool for chipping is parallel to the cross section of the main shaft of the machine tool, and is located in the same horizontal plane as the rotation axis of the main shaft;

[0010] Step 2.2, adjust the cutting edge, so that the cutting edge is in the same horizontal plane as the center line of the part, and is in the same vertical plane as the end face of the part;

[0011] Step 3, determine the machining parameters:

[0012] Set the locking tooth distribution angle, tool starting point, pitch, machine tool speed and cutting amount;

[0013] Determine the feed value: take the direction from the addendum to the dedendum of the locking tooth as the X direction, and determine the Z direction feed-in and feed-out coordinate points of the numerical control machine tool; the feed value l of each locking tooth surface center line and the end face is L-L', wherein L is the distance of the surface center section relative to the tail end face of the part, and L' is the feed value;

[0014] Step 4, rough machining;

[0015] Step 4.1, after the machine tool feeds l, set the X direction first machining amount, and in the process of one rotation of the machine tool main shaft, the tool repeatedly feeds in and out along the Z direction, and all tooth surfaces are completed once in the X direction. Continuous processing of one circle;

[0016] Step 4.2, set the X direction second machining amount, and the tool repeatedly feeds in and out along the Z direction, and all tooth surfaces are completed once in the X direction. Continuous processing of the second time;

[0017] Step 5, adjust the cutting amount parameter, and perform finish machining on all tooth surfaces according to step 4.

[0018] Further, the feed value L' in step 3 is obtained by calculation according to the formula , wherein p is the pitch, and alpha' is the included angle between the extension line of each locking tooth helical surface high-low point and the locking tooth center line.

[0019] Further, in step 3, the cutting amount is not greater than 0.05mm each time.

[0020] Further, the locking tooth angle in step 3 is obtained by measuring the head of the angle measuring instrument.

[0021] Further, in step 5, the harmonic oil is selected as the cutting fluid during finish machining to ensure the surface roughness requirement.

[0022] The beneficial effects of the present application are:

[0023] 1. The machining method of the present application uses the cutting mode of one point on the cutting edge and the tooth surface, reduces the cutting resistance and tool wear, and reduces the requirements for tool clamping.

[0024] 2、The processing method of the present application realizes the processing of all the locking tooth surfaces in one processing by setting the locking tooth angle position and the pitch and automatically processing the locking tooth surfaces by the numerical control gear shaping machine, avoids the multiple determination of the starting position of each spiral line, eliminates the mechanical transmission gap caused by repeated alignment, makes the locking tooth size stable and controllable, greatly improves the shape qualification rate, has good processing consistency, and the surface roughness can reach more than Ra1.6, and improves the processing quality of the locking tooth surface;

[0025] 3、The processing method of the present application adopts the numerical control integral processing mode, avoids the thousands of times of forward and reverse turning and tool feeding and withdrawing by manual operation, and does not need to strictly control the rotation angle of the machine tool spindle by human, thereby significantly reducing the processing time and cost, greatly reducing the workload of the operator, and improving the efficiency by about 86% compared with the original manual operation method, and can well realize the batch production of various types of key parts. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a flow chart of the processing method of the present application;

[0027] Figure 2 is a structure diagram of a locking mechanism;

[0028] Figure 3 is a partial sectional view of Figure 2 ;

[0029] Figure 4 is an angle distribution diagram of the center line of each locking tooth;

[0030] Figure 5 is a sectional view of Figure 4 ;

[0031] Figure 6 is a sectional view of Figure 4 ;

[0032] Figure 7 is an expansion diagram of the inclined surface to be processed in each locking tooth in Figure 4 relative to the center line;

[0033] BRIEF DESCRIPTION OF DRAWINGS: 1-No. 1 tooth, 2-No. 2 tooth, 3-No. 3 tooth, 4-No. 4 tooth, 5-No. 5 tooth, 6-locking tooth contact surface, 7-locking tooth. DETAILED DESCRIPTION

[0034] According to the application occasion and assembly relationship of different artillery, a plurality of locking teeth are distributed on the locking mechanism in the circumferential direction. Due to the influence of ammunition loading and shell ejection position, each locking tooth is unevenly distributed. In order to ensure the locking performance of the locking teeth, each locking tooth surface is a small-angle inclined surface with a certain pitch, so that the locking tooth surface is more closely and reliably fitted. The more the number of locking teeth is, the more complicated the processing process is. In addition, the distance precision between the center line of the locking tooth and the end face of the locking mechanism is usually required to be about 0.05mm, and the consistency precision of the distance between the plurality of tooth surfaces and the cross section of the locking mechanism is required to be within 0.04mm, and the surface roughness is usually required to be more than Ra1.6, so the machining difficulty of the spiral locking tooth surface is great.

[0035] Referring to Figures 1-7 A numerical control machining method for a spiral locking tooth surface of a locking mechanism, specifically comprising the following steps:

[0036] Step 1: Taking the direction from the tooth top to the tooth bottom of the locking tooth as the X direction size, calculating the feed value and taking it as the coordinate point of the Z direction feed of the numerical control machine tool: the feed value The feed value l of the tooth surface center line and the end face is l=L-L', wherein L is the distance of the tooth surface center section relative to the rear end face of the part, p is the pitch, and a' is the included angle between the extension line of the high and low points of each locking tooth spiral surface and the center line of the locking tooth;

[0037] Step 2: Clamping the part, centering the center frame, controlling the circular runout, clamping the part after sequentially tabulating and aligning the outer circle and the part end face, and adjusting the center frame to ensure that the workpiece does not move axially during the shaving;

[0038] Step 3: Clamping and aligning the tool, which is parallel to the cross section of the machine tool spindle and maintains the same horizontal plane as the spindle rotation axis;

[0039] Step 4: Adjusting the tool edge to maintain the same horizontal plane as the part center line, and statically aligning the tool edge to maintain the same vertical plane as the part end face;

[0040] Step 5: Converting the calculated feed and withdrawal coordinate point position information into the programming of the numerical control program, determining the tool starting point and pitch by measuring the angle with an angle measuring instrument and aligning the tool with the tail end face of the part with a block gauge, setting the machine tool speed and the cutting amount, and the spindle speed is 6-12r / min, and the cutting amount is not greater than 0.05mm each time during the shaving;

[0041] Step 6: After the tool alignment is completed, the numerical control program controls the feed l of the shaving machine tool, and then the shaving processing is performed.

[0042] Setting the first processing amount in the X direction, and in the process of one rotation of the machine tool spindle, the tool completes one continuous processing of the X direction circumference through multiple Z direction feed and withdrawal.

[0043] Step 7, set the X direction second machining amount, and the machine tool automatically performs the Z direction multiple feeding and retraction of the cutter according to step 6, to complete the second machining amount of all tooth surfaces;

[0044] Step 8, according to the finishing requirement, set the machining cutting amount and the spindle speed, repeat steps 6 to 7, and perform the finishing of all tooth surfaces.

[0045] The cutting amount is less than or equal to 0.03 mm, and the speed is 4-6 r / min.

[0046] The machining process of the method is divided into two stages of rough machining and finishing machining, and 0.05 mm machining allowance is left at the end of rough machining, and appropriate tool type, spindle speed and cutting amount are selected for finishing machining.

[0047] The finishing process of the method selects the blended oil as the cutting fluid to ensure the surface roughness requirement.

[0048] Next, taking the structure of double-row five closed teeth as an example and combining with the attached Figures 4-7 The method is described in detail.

[0049] Step 1, taking No. 4 tooth as a reference, the center line included angle of No. 1 and No. 2 teeth is 30°, the center line included angle of No. 3 and No. 5 teeth is 60°, the distance L of the tooth surface center section relative to the tail end surface of the part is 10 mm, the pitch p is 5 mm, and the feed value formula is used to calculate the parameters of the first row of teeth: The feed value formula l=L-L' is used to calculate the parameters of the first row of teeth, and table 1 is referred to:

[0050]

[0051] Table 1

[0052] Step 2, clamp the part, set the center frame, control the circular runout, and then clamp the part after table alignment of the outer circle and the part end surface, and adjust the center frame to ensure that the workpiece does not move axially during the shaving;

[0053] Step 3, the cutter is clamped and aligned, which is parallel to the cross section of the machine tool spindle and maintains the same horizontal plane as the spindle rotation axis;

[0054] Step 4, adjust the cutter edge to maintain the same horizontal plane as the part center line, and statically align the cutter to maintain the same vertical plane as the part end surface;

[0055] Step 5, the calculated feed and retraction coordinate point position information, i.e. α' in, α' out and feed value L', is converted into the programming of numerical control program, the angle is measured by an angle measuring instrument, the cutter is aligned with the part tail end surface by a block gauge, the cutter starting point and pitch are determined, the machine tool speed and cutting amount are set, the spindle speed is 6-12 r / min, and the cutting amount is not greater than 0.05 mm each time during shaving;

[0056] Step 6, after the end of the tool setting, the numerical control program controls the shoveling machine tool to feed the distance l, and then shoveling processing is performed.

[0057] The first X-direction processing amount is set to 0.05 mm, and in the process of one rotation of the machine tool spindle, the tool performs multiple Z-direction feed and retreat to complete one continuous processing of the X-direction circumference of all tooth surfaces;

[0058] Step 7, the second X-direction processing amount is set to 0.05 mm, and the machine tool automatically performs multiple Z-direction feed and retreat according to step 6 to complete the second processing amount of all tooth surfaces.

[0059] Step 8, according to the finishing requirement, the processing cutting amount is set to 0.02 mm and the spindle speed is set to 5 r / min, and steps 6 to 7 are repeated to perform finishing processing of all tooth surfaces.

[0060] After the first row of tooth processing is completed, the parameters of the second row of tooth calculated in advance are adjusted, and steps 5 to 8 are repeated to complete the processing of all tooth surfaces.

[0061] In summary, compared with the existing traditional method, the spiral locking tooth surface processing completed by using the present application reduces the processing time and cost, and improves the processing quality and efficiency of the locking tooth surface.

[0062] Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A method for numerically controlling the machining of a helical locking profile of a closure mechanism, characterized in that, The method comprises the following steps: Step 1, clamping the part, installing the center frame, and controlling the roundness; Step 2, tool setting, comprising the following sub-steps: Step 2.1, tool clamping alignment, making the tool body of the special tool for gashing parallel to the cross section of the main shaft of the machine tool and located in the same horizontal plane as the rotation axis of the main shaft; Step 2.2, adjusting the cutting edge, making the cutting edge keep the same horizontal plane as the center line of the part and keep the same vertical plane as the end surface of the part; Step 3, determining the machining parameters: Setting the distribution angle of the locking teeth, the starting point of the tool, the pitch, the speed of the machine tool and the cutting amount; Determination of the feed value: the direction of the closed tooth crest to the tooth bottom is the X direction, the Z direction feed-in and feed-out coordinate points of the numerical control machine tool are determined; the feed value l of each closed tooth surface center line to the end face tool is l=L-L ＇ , wherein L is the distance of the surface center section relative to the part tail end surface, L ＇ is the feed value; Step 4, rough machining of the locking tooth surface, comprising the following sub-steps: Step 4.1, after the gashing machine tool feeds l, setting the first machining amount in the X direction, during the rotation of the main shaft of the machine tool for one revolution, the tool repeatedly feeds and retreats in the Z direction for multiple times, and all tooth surfaces are processed once in the X direction; Step 4.2, setting the second machining amount in the X direction, the tool repeatedly feeds and retreats in the Z direction for multiple times, and all tooth surfaces are processed once in the X direction for the second time; Step 5, setting the cutting amount and the speed of the main shaft of the machine tool according to the requirement of the finishing, and finishing all tooth surfaces according to step 4.

2. The method of claim 1, wherein the helical closure spline is formed by a computer numerical control (CNC) machining process. The feed value L in step 3 ＇ According to the formula The calculation is obtained, where p is the pitch, and a' is the angle between the extension line of each locking tooth helical surface high and low point and the center line of the locking tooth.

3. The method of claim 1, wherein the method further comprises: In step 3, the cutting amount is not more than 0.05mm each time.

4. The method of claim 1, wherein the method further comprises: In step 3, the angle of the locking teeth is obtained by the measuring head of the angle measuring instrument.

5. The method of claim 1, wherein, In step 5, the finishing is carried out by selecting the blending oil as the cutting fluid to ensure the surface roughness requirement.

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