Tooth groove grinding clamp for high-load connecting rod tooth groove precision machining and machining method of tooth groove grinding clamp

Abstract

The invention relates to a tooth groove grinding clamp for high-load connecting rod tooth groove precision machining and a machining method of the tooth groove grinding clamp. The tooth groove grinding clamp used for high-load connecting rod tooth groove precision machining comprises a bottom plate used for supporting and fixing the tooth groove grinding clamp, and the bottom plate fixes the tooth groove grinding clamp to a machine tool for grinding through bolts and nuts; the vertical plate is vertically and upwards arranged on the bottom plate; the connecting rod body fixing assembly is arranged on one side face of the vertical plate and used for fixing a connecting rod body to be machined; the connecting rod cover fixing assembly is arranged on the other side face, opposite to the connecting rod body fixing assembly, of the vertical plate and used for fixing a connecting rod cover to be machined, and when the connecting rod body to be machined and the connecting rod cover are positioned, the connecting rod body to be machined and the connecting rod cover are staggered by one half of the tooth pitch. According to the tooth groove grinding clamp for high-load connecting rod tooth groove precision machining, a connecting rod body and a connecting rod cover are clamped for tooth grinding machining, tooth grooves of the connecting rod body and the cover can be ground at the same time, and it is guaranteed that the tooth shapes of the connecting rod body and the cover are consistent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of connecting rod tooth groove machining, in particular to a tooth groove grinding clamp for precision machining of high-load connecting rod tooth grooves and a machining method thereof. BACKGROUND

[0002] The connecting rod is one of the key core components in a diesel engine, which is usually composed of a connecting rod body, a connecting rod cover, a connecting rod bolt, a connecting rod bushing and the like. Among them, the positioning methods of the connecting rod body and the connecting rod cover include tooth groove method, mortise and tenon method, pin hole method, etc. The tooth groove method is adopted for positioning the connecting rod cover and the rod body of the high-speed and high-power diesel engine of 1000 kW or more, which can make the connecting rod bear greater load during work, and the large hole is not easy to deform, thereby ensuring the normal work of the connecting rod. At this time, the tooth groove machining precision and the fit degree of the connecting rod body and the connecting rod cover are required to be high, so as to ensure the machining and reassembly precision of the connecting rod large hole. Figure 1a and 1b As shown in the figure, it is a schematic diagram of tooth groove machining precision requirement.

[0003] At present, the methods for machining tooth grooves include milling, wire cutting and grinding, etc. The machining methods of milling and wire cutting usually cannot meet the precision requirements of the connecting rod tooth groove of the high-speed and high-power diesel engine, especially the surface roughness and the fit degree of the rod and the cover, which are far from the requirements (roughness ≥ Ra1.6, fit degree ≤ 70%), even if the method of grinding the teeth on the rod and the cover respectively is adopted, it cannot completely meet the requirements, and the fit degree is out of tolerance, the teeth are wrong, and the yield is less than 70%. When the grinding method is adopted, the tooth grooves of the connecting rod body and the connecting rod cover are ground and machined respectively, the grinding wheel is machined in the form of one tooth shape and one tooth shape in the difference compensation mode, the cumulative error is large, and the machined tooth groove will also appear mismatching.

[0004] Therefore, it is urgent to develop a machining method for precision machining of high-load connecting rod tooth grooves, which can meet the precision requirements of the tooth groove machining and ensure the matching of the tooth groove. SUMMARY

[0005] The technical problem to be solved by the present application is how to precisely machine the high-load connecting rod tooth groove to meet the precision requirements of the tooth groove machining and ensure the matching of the tooth groove.

[0006] To solve the above technical problems, according to one aspect of the present application, a precision grinding jig for high-load connecting rod tooth groove machining is provided, wherein the high-load connecting rod tooth groove to be machined includes a tooth groove on a connecting rod body and a tooth groove on a connecting rod cover, and the precision grinding jig includes: a base plate for supporting and fixing the precision grinding jig, the base plate being fixed on a grinding machine by bolts and nuts; a vertical plate vertically arranged on the base plate; a connecting rod body fixing assembly arranged on one side of the vertical plate and used for fixing the connecting rod body to be machined, wherein the tooth groove to be machined is upward and higher than the top end of the vertical plate after the connecting rod body to be machined is fixed; a connecting rod cover fixing assembly arranged on the other side of the vertical plate opposite to the connecting rod body fixing assembly and used for fixing the connecting rod cover to be machined, wherein the tooth groove to be machined is upward and higher than the top end of the vertical plate after the connecting rod cover to be machined is fixed, and wherein the connecting rod body and the connecting rod cover to be machined are positioned with a half-tooth pitch offset, so as to ensure the consistency of the tooth shapes of the connecting rod body and the connecting rod cover and to realize simultaneous grinding machining of the tooth grooves of the connecting rod body and the connecting rod cover.

[0007] According to an embodiment of the present application, the connecting rod body fixing assembly can include: a first side support arranged on one side of the vertical plate and abutting against one side edge of the connecting rod body to be machined, so as to fix the position of the one side edge of the connecting rod body to be machined; a support, a handle and a top rod, wherein the support is arranged on the side of the vertical plate, the handle and the top rod are fixedly connected, the top rod is fixed in the support by operating the handle, and the top rod abuts against the other side edge of the connecting rod body to be machined; and a small-head support arranged on one side of the vertical plate and used for fixing the connecting rod body to be machined from the bottom.

[0008] According to an embodiment of the present application, the connecting rod cover fixing assembly can include: a second side support arranged on the other side of the vertical plate and abutting against one side edge of the connecting rod cover to be machined, so as to fix the position of the one side edge of the connecting rod body to be machined; another set of supports, handles and top rods, wherein the top rods abut against the other side edge of the connecting rod cover to be machined; and a lower support arranged on the other side of the vertical plate and used for fixing the connecting rod cover to be machined from the bottom, wherein the first side support and the second side support are arranged on the two opposite sides of the vertical plate, and the difference between the half widths of the first side support and the second side support is a half-tooth pitch, so as to ensure the consistency of the tooth shapes of the connecting rod body and the connecting rod cover and to realize simultaneous grinding.

[0009] According to an embodiment of the present application, the precision grinding jig for high-load connecting rod tooth groove machining can further include: a bottom support arranged between the connecting rod body to be machined and the vertical plate or arranged between the connecting rod cover to be machined and the vertical plate; and two open pressing plates arranged on the opposite two outer sides of the connecting rod body and the connecting rod cover to be machined, the two open pressing plates being tightened by bolts and nuts, so as to press the connecting rod body and the connecting rod cover to be machined in a direction perpendicular to the vertical plate.

[0010] According to the embodiment of the present application, the gear grinding fixture for high-load connecting rod tooth groove precision machining can further comprise: a reinforcing rib in the shape of a right-angled triangle, wherein two right-angled sides are connected to the bottom plate and the vertical plate respectively to fix the relative positions of the bottom plate and the vertical plate, so that the vertical plate is more stable relative to the machine tool for grinding. Preferably, a plurality of reinforcing ribs are provided, which are preferably provided on both sides of the vertical plate, and the number of reinforcing ribs can be determined according to the user's needs.

[0011] According to another aspect of the present application, a machining method for high-load connecting rod tooth groove precision machining is provided. The machining method adopts a numerical control tooth groove grinding machine to machine the connecting rod tooth groove, and adopts the gear grinding fixture for high-load connecting rod tooth groove precision machining according to any one of claims 1-5 to position and fix the connecting rod body and the connecting rod cover to be machined. Two grinding wheels are installed on the grinding wheel spindle of the numerical control tooth groove grinding machine. The two grinding wheels are separated by a sleeve provided between the two grinding wheels and two adjusting shims located on both sides of the sleeve. By replacing adjusting shims with different thicknesses, the gap between the two grinding wheels can be adjusted to meet the machining requirements of the tooth spacing on both sides of the connecting rod body or the connecting rod cover, so as to realize the simultaneous machining of the tooth grooves on both sides of the connecting rod body or the connecting rod cover, and the simultaneous machining of the tooth grooves on the same side of the connecting rod body and the connecting rod cover. Before machining, the grinding surface of the grinding wheel is dressed with a diamond roller to form a tooth shape. The tooth shape of the diamond roller is consistent with the tooth shape pattern of the connecting rod body and the connecting rod cover to be machined, so as to ensure that the connecting rod tooth groove is consistent with the pattern during grinding.

[0012] According to the embodiment of the present application, the machining method for high-load connecting rod tooth groove precision machining can comprise the following steps: S1, checking and adjusting the accuracy of the grinding wheel shaft and the roller shaft to ensure that the radial runout of the grinding wheel shaft and the roller shaft is ≤0.007, and the axial runout of the grinding wheel shaft and the roller shaft is ≤0.02; S2, placing the fixture on the machine tool, adsorbing the magnetic table stand equipped with a dial gauge on the machine tool spindle, and aligning the fixture to make the planes of the lower support and the small head support in contact with the workpiece parallel to the machine tool spindle, with a parallelism ≤0.005. After alignment, the fixture is fixed on the machine tool with nuts; S3, respectively fitting the outer shape of the connecting rod body and the connecting rod cover to be machined with the side support. First, the handle is used to slightly pre-tighten the top rod to ensure that the outer shape of the connecting rod body and the connecting rod cover is tightly fitted with the side support, and then the connecting rod body and the connecting rod cover are clamped with bolts, nuts, and open clamps; S4, running the grinding wheel automatic balancing program to confirm that the grinding wheel is in a balanced state, and then running the machining program; S5, performing tooth groove grinding. First, the tooth groove is coarsely ground, and the cooling liquid is kept sufficient, with a remaining amount of 0.08mm. After coarse grinding, the grinding wheel is dressed; S6, precisely grinding the tooth groove according to the parameters, and keeping the cooling liquid sufficient; S7, stopping the machine tool after grinding is completed, taking down the connecting rod body and the connecting rod cover, and performing inspection.

[0013] According to the embodiment of the present application, the machining method for high-load connecting rod tooth groove precision machining can further comprise the following steps: before tooth groove grinding, the accuracy of the grinding wheel shaft and the roller shaft is adjusted to ensure that the radial runout of the grinding wheel shaft and the roller shaft is less than or equal to 0.007 mm, and the axial movement of the grinding wheel shaft and the roller shaft is less than or equal to 0.02 mm; the tooth groove grinding is divided into coarse grinding and fine grinding, a total of two times, and the grinding wheel is adjusted each time the grinding is completed, the adjustment amount of the grinding wheel should be greater than the total tooth height, and the adjustment speed is 1 um / rev; the grinding allowance reserved for the fine grinding after the coarse grinding is 0.08 mm; the peristaltic grinding mode is used during the fine grinding, and the grinding speed is 2 um / rev; before grinding, the automatically balanced program of the grinding wheel is run to confirm that the grinding wheel is in a balanced state.

[0014] According to the embodiment of the present application, when the tooth groove is machined, cooling is simultaneously performed, the pressure of the equipment cooling system can be 10 MPa, the cooling nozzle with a width greater than the width of the tooth groove can be used for cooling, and the cooling pump draws the cooling liquid from the cooling water tank of the machine tool, impacts the entire grinding tooth surface through the pipeline through the cooling nozzle, carries away a large amount of grinding heat, makes the cooling more sufficient, avoids the generation of thermal deformation, and better guarantees the tooth shape precision.

[0015] According to the embodiment of the present application, the numerical control tooth groove grinder for machining can be BC-12.

[0016] Compared with the prior art, the technical scheme provided by the embodiment of the present application can at least achieve the following beneficial effects:

[0017] According to the tooth groove grinding clamp for high-load connecting rod tooth groove precision machining of the present application, the clamping and positioning are reliable and high in precision, the tooth grooves of the body and the cover are simultaneously ground by staggering one-half of the tooth pitch, the error accumulation is reduced, and the fit of the teeth is better; two formed grinding wheels are used, the distance between the two grinding wheels is adjusted by adjusting the gaskets to ensure the tooth spacing requirement, the tooth groove grinding of the connecting rod body and the connecting rod cover is completed at one time, the error accumulation caused by the differential grinding is avoided, the peristaltic grinding mode is used, the grinding method, the grinding wheel adjustment parameter, the grinding wheel dynamic balance, the grinding wheel shaft and the roller shaft accuracy determination, the grinding allowance, and the grinding parameter matching are determined, and the machining precision of the high-load connecting rod tooth groove is improved.

[0018] The machining method for high-load connecting rod tooth groove precision machining according to the present application is characterized in that the rough grinding and the fine grinding are both profile grinding, the tooth position, precision and meshing precision are guaranteed by the fixture and the grinding parameters, and the tooth profile is guaranteed by the dressing grinding wheel and the grinding wheel.

[0019] The machining method for high-load connecting rod tooth groove precision machining according to the present application is characterized in that the machining method is used for tooth groove machining test verification, the machined tooth groove meets the pattern requirements, no tooth error phenomenon is found, the roughness is between Ra0.63-Ra0.4, the fit degree is not less than 90%, batch verification shows that the machined tooth groove meets the pattern requirements by 100%, the adoption of the new process method effectively improves the tooth groove machining precision and the yield, and improves the high connecting rod reliability of the high-speed and high-power diesel engine. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below, and obviously, the drawings in the following description only relate to some embodiments of the present application, but not limit the present application.

[0021] Figures 1a-1b is a tooth groove machining precision requirement schematic diagram;

[0022] Figure 2a is a main view of a tooth groove grinding fixture for high-load connecting rod tooth groove precision machining according to an embodiment of the present application;

[0023] Figure 2b is a left view of Figure 2a ;

[0024] Figure 2c is a right view of Figure 2a ;

[0025] Figure 3 is a roller grinding wheel schematic diagram according to an embodiment of the present application;

[0026] Figure 4 is a cooling schematic diagram according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0028] Unless otherwise defined, technical terms or scientific terms used herein should be understood as having the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms "first", "second" and similar terms used in the description and claims of the present patent application do not denote any order, quantity or importance, but are used to distinguish different components. Similarly, the terms "one" or "a" or similar terms do not denote a quantity limitation, but mean at least one.

[0029] Figure 2a is a front view of a gear grinding jig for high-load connecting rod gear slot precision machining according to an embodiment of the present application; Figure 2b is a left view of Figure 2a ; Figure 2c is a right view of Figure 2a .

[0030] As shown in Figures 2a to 2c , the high-load connecting rod gear slot to be machined includes a gear slot on the connecting rod body and a gear slot on the connecting rod cover, and the gear grinding jig for high-load connecting rod gear slot precision machining includes a base plate 1, a vertical plate 2, a connecting rod body fixing assembly and a connecting rod cover fixing assembly.

[0031] The base plate 1 is used for supporting and fixing the gear grinding jig, and the base plate 1 is fixed on the machine tool for grinding by bolts and nuts; the vertical plate 2 is vertically arranged on the base plate 1.

[0032] The connecting rod body fixing assembly is arranged on one side of the vertical plate 2, and is used for fixing the connecting rod body to be machined, wherein after the connecting rod body to be machined is fixed, the gear slot to be ground is upward and higher than the top end of the vertical plate 2; the connecting rod cover fixing assembly is arranged on the other side of the vertical plate 2 opposite to the connecting rod body fixing assembly, and is used for fixing the connecting rod cover to be machined, wherein after the connecting rod cover to be machined is fixed, the gear slot to be ground is upward and higher than the top end of the vertical plate 2.

[0033] Wherein, when the connecting rod body and the connecting rod cover to be machined are positioned, they are staggered by one-half pitch, so as to ensure that the tooth shapes of the connecting rod body and the connecting rod cover are consistent, so as to realize grinding machining of the gear slots of the connecting rod body and the connecting rod cover at the same time.

[0034] According to one or some embodiments of the present application, the connecting rod body fixing assembly comprises a first side support 3, a small head support 4, a support 5, a handle 6 and a top rod 7.

[0035] The first side support 3 is arranged on one side of the vertical plate 2 and abuts against one side of the connecting rod body to be machined, so as to fix the position of one side of the connecting rod body to be machined.

[0036] The support 5 is arranged on the side of the vertical plate 2, and the handle 6 and the top rod 7 are fixedly connected. The top rod 7 is fixed in the support 5 by operating the handle 6, and abuts against the other side of the connecting rod body to be machined.

[0037] The small head support 4 is arranged on one side of the vertical plate 2, and is used to fix the connecting rod body to be machined from the bottom.

[0038] According to one or some embodiments of the present application, the connecting rod cover fixing assembly comprises a second side support 8, a lower support 9, a support 5, a handle 6 and a top rod 7.

[0039] The second side support 8 is arranged on the other side of the vertical plate 2 and abuts against one side of the connecting rod cover to be machined, so as to fix the position of one side of the connecting rod cover to be machined.

[0040] The other set of support 5, handle 6 and top rod 7 abut against the other side of the connecting rod cover to be machined by the top rod 7.

[0041] The lower support 9 is arranged on the other side of the vertical plate 2 and is used to fix the connecting rod cover to be machined from the bottom.

[0042] The first side support and the second side support are arranged on the two opposite sides of the vertical plate 2 and fixed on the vertical plate 2. The difference between the half widths of the first side support and the second side support is one half of the pitch, so that the tooth shapes of the connecting rod body and the connecting rod cover are consistent, and the simultaneous grinding is realized.

[0043] According to one or some embodiments of the present application, the gear grinding jig for precise machining of the high-load connecting rod tooth groove further comprises a bottom support 11 and an open pressing plate 10.

[0044] The bottom support 11 is arranged between the connecting rod body to be machined and the vertical plate 2, or arranged between the connecting rod cover to be machined and the vertical plate 2.

[0045] Two open pressing plates 10 are arranged on the opposite two outer sides of the connecting rod body and the connecting rod cover, and the two open pressing plates 10 are tightened by bolts and nuts, so as to press the connecting rod body and the connecting rod cover in the direction perpendicular to the vertical plate 2.

[0046] According to one or more embodiments of the present invention, the grinding fixture for precision machining of high-load connecting rod tooth grooves further includes: a reinforcing rib 12. The reinforcing rib 12 is a right-angled triangle, wherein the two right-angled sides are respectively connected to the base plate 1 and the vertical plate 2 to fix the relative position of the base plate 1 and the vertical plate 2, making the vertical plate 2 more stable relative to the machine tool used for grinding. Multiple reinforcing ribs 12 can be provided, preferably on both sides of the vertical plate 2, but this is not limited to the specific requirements of the user.

[0047] The gear grinding fixture for precision machining of high-load connecting rod tooth grooves according to the present invention provides reliable clamping and positioning with high precision. By simultaneously grinding the tooth grooves of the connecting rod body and the connecting rod cap with a staggered tooth pitch of half, error accumulation is reduced and the tooth-to-tooth fit is improved. The grinding wheel 13 uses two forming grinding wheels 13, and the distance between the two grinding wheels 13 is adjusted by adjusting shims 16 to ensure the tooth pitch requirement. The gear groove grinding of the connecting rod body and the connecting rod cap is completed in one go, forming in one go, avoiding the error accumulation of using offset grinding. The peristaltic grinding method is adopted, and the grinding method, grinding wheel 13 dressing parameters, grinding wheel 13 dynamic balancing, grinding wheel shaft 14 and roller shaft 17 precision determination, grinding allowance, and grinding parameter matching are improved, thereby improving the machining accuracy of high-load connecting rod tooth grooves.

[0048] Figure 3 This is a schematic diagram showing a roller grinding wheel 13 according to an embodiment of the present invention.

[0049] like Figure 3 As shown, the machining method for precision machining of high-load connecting rod tooth grooves employs a CNC tooth groove grinding machine. A grinding fixture for precision machining of high-load connecting rod tooth grooves, as described in any one of claims 1-5, is used to position and fix the connecting rod body and connecting rod cap to be machined. Two grinding wheels 13 are mounted on the spindle of the CNC tooth groove grinding machine. The two grinding wheels 13 are separated by a sleeve 15 positioned between them and two adjusting shims 16 located on both sides of the sleeve 15. By replacing the adjusting shims 16 with different thicknesses, the gap between the two grinding wheels 13 can be adjusted to meet the machining requirements of the tooth spacing on both sides of the connecting rod body or connecting rod cap, thereby achieving simultaneous machining of tooth grooves on both sides of the connecting rod body or connecting rod cap, as well as simultaneous machining of tooth grooves on the same side of the connecting rod body and connecting rod cap. The grinding surface of the grinding wheel 13 is dressed into a tooth shape using a diamond roller 18. The tooth shape of the diamond roller 18 is consistent with the tooth shape drawing of the connecting rod body and connecting rod cap to be machined, so as to ensure that the connecting rod tooth groove is consistent with the drawing during grinding.

[0050] According to one or more embodiments of the present invention, a machining method for precision machining of high-load connecting rod tooth grooves includes the following steps:

[0051] S1, check and adjust the accuracy of the grinding wheel shaft 14 and the roller shaft 17, ensure that the radial runout of the grinding wheel shaft 14 and the roller shaft 17 is ≤0.007, and the axial movement of the grinding wheel shaft 14 and the roller shaft 17 is ≤0.02;

[0052] S2, place the clamp on the machine tool, adsorb the magnetic table stand equipped with a dial gauge on the machine tool spindle, and align the clamp, so that the planes of the lower support 9 and the small head support 4 in contact with the workpiece are parallel to the machine tool spindle, and the parallelism is ≤0.005, and after alignment, the clamp is fixed on the machine tool with nuts;

[0053] S3, respectively, the connecting rod body and the connecting rod cover profile to be processed are well fitted with the side support, the handle 6 is used to slightly pre-tighten the top rod 7, and after ensuring that the connecting rod body and the connecting rod cover profile are tightly fitted with the side support, the connecting rod body and the connecting rod cover are clamped with bolts, nuts and open clamps 10;

[0054] S4, run the automatic balancing program of the grinding wheel 13, confirm that the grinding wheel 13 is in a balanced state, and then run the machining program;

[0055] S5, tooth groove grinding, first rough grinding tooth groove, keep sufficient cooling liquid, and leave a margin of 0.08mm, after rough grinding, trim the grinding wheel 13;

[0056] S6, fine grinding of the tooth groove according to the parameters, and keeping sufficient cooling liquid;

[0057] S7, the machine tool stops after grinding is completed, the connecting rod body and the connecting rod cover are taken down, and inspection is performed.

[0058] According to one or some embodiments of the application, the machining method for precision machining of high-load connecting rod tooth grooves further comprises the following steps:

[0059] Before tooth groove grinding, first adjust the accuracy of the grinding wheel shaft 14 and the roller shaft 17, ensure that the radial runout of the grinding wheel shaft 14 and the roller shaft 17 is ≤0.007mm, and the axial movement of the grinding wheel shaft 14 and the roller shaft 17 is ≤0.02mm;

[0060] Tooth groove grinding is divided into rough grinding and fine grinding, a total of 2 times, and the grinding wheel 13 is trimmed once after each grinding is completed, the trimming amount of the grinding wheel 13 should be greater than the total tooth height, and the trimming speed is 1um / rev; the grinding allowance reserved for fine grinding after rough grinding is 0.08mm; during fine grinding, peristaltic grinding mode is adopted, and the grinding speed is 2um / rev;

[0061] Before grinding, first run the automatically balanced program of the grinding wheel 13 set in advance, and confirm that the grinding wheel 13 is in a balanced state.

[0062] According to the machining method for high-load connecting rod tooth groove precision machining, the rough grinding and the fine grinding are both profile grinding, the tooth position, precision and meshing precision are guaranteed by the fixture and grinding parameters, and the tooth profile is guaranteed by the dressing grinding wheel 13 and the grinding wheel 13. The tooth groove machining test verification is carried out by using the machining method for high-load connecting rod tooth groove precision machining, the machined tooth groove meets the pattern requirements, no tooth error phenomenon is found, the roughness is between Ra0.63-Ra0.4, the fit degree is not less than 90%, after batch verification, the machined tooth groove meets the pattern requirements by 100%, the adoption of the new process method effectively improves the tooth groove machining precision and the yield, and improves the high connecting rod reliability of the high-speed and high-power diesel engine.

[0063] Figure 4 is a cooling schematic diagram according to an embodiment of the application.

[0064] As Figure 4 shown, the tooth groove machining is carried out synchronously with cooling, wherein the equipment cooling system pressure is 10 MPa, the cooling nozzle 19 with a width greater than the tooth groove width is used for cooling, the cooling pump draws the cooling liquid from the machine tool cooling water tank, and the cooling liquid is impacted on the entire grinding tooth surface through the pipe and the cooling nozzle 19, a large amount of grinding heat is taken away, the cooling is more sufficient, the generation of thermal deformation is avoided, and the tooth profile precision is better guaranteed.

[0065] According to one or some embodiments of the application, the numerical control tooth groove grinder used for machining is of the BC-12 type.

[0066] According to the machining method for high-load connecting rod tooth groove precision machining, when used, the product pattern requirements are met by 100%, the numerical control grinder with high precision is selected according to the equipment of the application, the cooling system is strong, the fixture has high precision and no clamping deformation, the machining of the connecting rod body and the cover tooth groove can be completed at one time, the machining precision is not affected by the two clamping errors, the tooth groove shape precision is guaranteed by the grinding wheel shape, the grinding wheel shape is guaranteed by the roller dressing, the repeated positioning error is avoided, the tooth spacing is guaranteed by the positions of the two grinding wheels, the repeated positioning error is avoided, and the grinding is divided into two processes of rough grinding and fine grinding, and the grinding allowance distribution is suitable.

[0067] The above merely describes exemplary embodiments of the application, but is not used to limit the protection scope of the application, and the protection scope of the application is determined by the appended claims.

Claims

1. A gear grinding fixture for precision machining of high load connecting rod journals, wherein, The high-load connecting rod tooth groove to be processed includes a tooth groove on a connecting rod body and a tooth groove on a connecting rod cover, and the tooth grinding fixture comprises: a bottom plate for supporting and fixing the tooth grinding fixture, the bottom plate fixing the tooth grinding fixture on a machine tool for grinding through bolts and nuts; a vertical plate vertically arranged on the bottom plate; a connecting rod body fixing assembly arranged on one side of the vertical plate for fixing the connecting rod body to be processed, wherein the tooth groove to be ground is upward and higher than the top end of the vertical plate after the connecting rod body to be processed is fixed; a connecting rod cover fixing assembly arranged on the other side of the vertical plate opposite to the connecting rod body fixing assembly for fixing the connecting rod cover to be processed, wherein the tooth groove to be ground is upward and higher than the top end of the vertical plate after the connecting rod cover to be processed is fixed, wherein the connecting rod body and the connecting rod cover to be processed are positioned with a half-tooth pitch offset, so as to ensure the consistency of the tooth shape of the connecting rod body and the connecting rod cover, thereby realizing the simultaneous grinding of the tooth grooves of the connecting rod body and the connecting rod cover.

2. The gear broaching fixture for high load connecting rod journal precision machining of claim 1, wherein, The connecting rod body fixing assembly comprises: a first side support arranged on one side of the vertical plate and abutting against one side of the connecting rod body to be processed for fixing the position of one side of the connecting rod body to be processed; a support, a handle and a top rod, wherein the support is arranged on the side of the vertical plate, the handle and the top rod are fixedly connected, the top rod is fixed in the support by operating the handle, and the top rod abuts against the other side of the connecting rod body to be processed; a small head support arranged on one side of the vertical plate for fixing the connecting rod body to be processed from the bottom.

3. The gear broaching fixture for high load connecting rod journal precision machining of claim 2, wherein, The connecting rod cover fixing assembly comprises: a second side support arranged on the other side of the vertical plate and abutting against one side of the connecting rod cover to be processed for fixing the position of one side of the connecting rod body to be processed; another set of supports, handles and top rods, wherein the top rod abuts against the other side of the connecting rod cover to be processed; a lower support arranged on the other side of the vertical plate for fixing the connecting rod cover to be processed from the bottom, wherein the first side support and the second side support are fixed on the vertical plate on the two sides of the vertical plate in correspondence, and the difference between the half widths of the first side support and the second side support is a half tooth pitch, so as to ensure the consistency of the tooth shape of the connecting rod body and the connecting rod cover, thereby realizing the simultaneous grinding.

4. The tooth grinding fixture for precise machining of high-load connecting rod tooth grooves according to claim 3, further comprising: a bottom support arranged between the connecting rod body to be processed and the vertical plate or arranged between the connecting rod cover to be processed and the vertical plate; two open pressing plates arranged on the opposite two outer sides of the connecting rod body and the connecting rod cover, and the two open pressing plates are tightened by bolts and nuts to press the connecting rod body and the connecting rod cover in a direction perpendicular to the vertical plate.

5. The gear broaching fixture for high load connecting rod journal precision machining of claim 1, further comprising: A reinforcing rib in the shape of a right-angled triangle, wherein two right-angled sides are connected to the bottom plate and the vertical plate respectively to fix the relative positions of the bottom plate and the vertical plate, so that the vertical plate is more stable relative to the machine tool for grinding.

6. A machining method for precision machining of high load connecting rod spline, the machining method uses a numerical control spline grinding machine to machine the connecting rod spline, uses the grinding spline fixture for precision machining of high load connecting rod spline according to any one of claims 1-5 to position and fix the connecting rod body and the connecting rod cover to be machined, two grinding wheels are installed on the grinding wheel spindle of the numerical control spline grinding machine, the two grinding wheels are separated by a sleeve set between the two grinding wheels and two adjusting shims located on both sides of the sleeve, wherein, By replacing the adjusting shims with different thickness, the gap between the two grinding wheels can be adjusted to meet the machining requirements of the tooth spacing on both sides of the connecting rod body or the connecting rod cover, thereby realizing the simultaneous machining of the tooth grooves on both sides of the connecting rod body or the connecting rod cover, and the simultaneous machining of the tooth grooves on the same side of the connecting rod body and the connecting rod cover.

7. The machining method for high-load connecting rod tooth groove precision machining according to claim 6, comprising the following steps: S1, checking and adjusting the accuracy of the grinding wheel shaft and the roller shaft, ensuring that the radial runout of the grinding wheel shaft and the roller shaft is ≤0.007, and the axial movement of the grinding wheel shaft and the roller shaft is ≤0.02; S2, placing the clamp on the machine tool, adsorbing the magnetic table stand equipped with a dial gauge on the machine tool spindle, and aligning the clamp, so that the planes of the lower support and the small head support in contact with the workpiece are parallel to the machine tool spindle, and the parallelism is ≤0.005, and after alignment, the clamp is fixed on the machine tool with nuts; S3, respectively attaching the connecting rod body and the connecting rod cover to be machined to the side supports, first slightly pre-tightening the top rod with the handle, and then respectively clamping the connecting rod body and the connecting rod cover with bolts, nuts and split clamps after ensuring that the connecting rod body and the connecting rod cover are tightly attached to the side supports; S4, running the grinding wheel automatic balancing program to confirm that the grinding wheel is in a balanced state, and then running the machining program; S5, tooth groove grinding, first rough grinding the tooth groove, keeping the cooling liquid sufficient, and leaving a margin of 0.08mm, and after rough grinding, dressing the grinding wheel; S6, fine grinding the tooth groove according to the parameters, keeping the cooling liquid sufficient; S7, stopping the machine tool after grinding is completed, and taking out the connecting rod body and the connecting rod cover for inspection.

8. The machining method for high-load connecting rod tooth groove precision machining according to claim 7, further comprising the following steps: Before tooth groove grinding, first adjusting the accuracy of the grinding wheel shaft and the roller shaft, ensuring that the radial runout of the grinding wheel shaft and the roller shaft is ≤0.007mm, and the axial movement of the grinding wheel shaft and the roller shaft is ≤0.02mm; Tooth groove grinding is divided into rough grinding and fine grinding, a total of 2 times, and the grinding wheel is dressed once after each grinding is completed, the dressing amount of the grinding wheel should be greater than the full tooth height, and the dressing speed is 1um / rev; the grinding allowance reserved for fine grinding after rough grinding is 0.08mm; during fine grinding, peristaltic grinding mode is adopted, and the grinding speed is 2um / rev; Before grinding, the grinding wheel automatic balancing program is run to confirm that the grinding wheel is in a balanced state.

9. The machining method for precision machining of high load connecting rod big end pockets of claim 6 wherein, When tooth groove machining is performed, cooling is simultaneously performed, wherein the pressure of the equipment cooling system is 10MPa, a cooling nozzle with a width greater than the width of the tooth groove is used for cooling, and the cooling pump draws the cooling liquid from the cooling water tank of the machine tool, and through the pipeline, the cooling liquid impacts and covers the entire grinding tooth surface through the cooling nozzle, carries away a large amount of grinding heat, makes the cooling more sufficient, avoids the generation of thermal deformation, and better guarantees the tooth profile accuracy.

10. The machining method for precision machining of high load connecting rod big end socket of claim 6 wherein, The numerical control tooth groove grinder is of BC-12 type.

Images