A V-shaped cylinder sleeve fitting positioning clamp and process method

Abstract

The present application relates to a kind of V-shaped cylinder liner fitting positioning clamps and process method, solve the position degree deviation problem that the relative position of pre-cast cylinder liner in cylinder, clamp includes 2 groups of split X direction centring positioning module, 2 groups of split Y direction centring positioning module, Z direction positioning point, Z direction auxiliary support;Positioning point X1, X2 in X direction centring clamp 1 make 1, 6 cylinder hole center centring positioning, positioning point X3, X4 in X direction centring clamp 2 make 3, 4 cylinder hole center centring positioning, reach the intersection line of the plane formed by the center line of two side cylinder holes respectively and the relative coincidence of clamp center;Positioning point Y1, Y2 in Y direction centring clamp 1 make 1, 3 cylinder center centring positioning, positioning point Y3, Y4 in Y direction centring clamp 2 make 4, 6 cylinder center centring positioning, reach the midpoint of the center of two side cylinder holes and the minimum deviation of design center;Z direction uses three-point support and one-point auxiliary support as positioning and clamping point.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cylinder liner, and relates to a V-shaped cylinder liner fitting positioning clamp and a process method. BACKGROUND

[0002] A commonly used manufacturing process for a V-shaped cylinder is a cylinder liner embedding method (liner inserting process). The manufacturing process used in the production of an aluminum alloy V-shaped cylinder is as follows: blank preparation, rough machining of the blank shape, semi-finishing of the cylinder liner hole, press fitting of the cylinder liner, finishing of the cylinder liner and other features, and honing of the cylinder liner. When the engine is in operation, the cylinder liner is affected by factors such as changes in operating temperature, friction with the piston, vibration, the size of the interference during press fitting, the machining precision (dimensional accuracy, roundness, cylindricity) of the cylinder hole and the piston outer circle, and the cylinder liner may become loose and axially displaced, causing abnormal engine noise and even engine failure.

[0003] To improve the performance of the engine, high-end engines use a cylinder liner integrated casting process, which solves the shortcomings of the liner inserting process by casting the cylinder liner and the cylinder blank together. However, the position of the cylinder liner in the integrated cast cylinder is affected by factors such as the dimensional accuracy of the sand core, the gap between the sand core and the pre-installed cylinder liner, the distribution of the positioning points on multiple sand cores, and the gap error during sand core assembly. The pre-cast cylinder liner may have positional deviation in the relative position of the cylinder, resulting in uneven wall thickness of the machined cylinder liner, which greatly affects the engine's thermal management system and can cause problems such as increased oil consumption, cylinder seizure, cylinder explosion, and reduced engine life.

[0004] The original V-shaped cylinder machining process: X, Y, and Z positioning points are on multiple sand cores. Due to manufacturing and assembly errors, it is impossible to ensure the accuracy of the positioning reference and the center position of the cylinder liner. Therefore, the 6-point cylinder shape machining process as a positioning reference is not suitable for high-precision cylinder liner machining. SUMMARY

[0005] The application solves the problem of positional deviation of the pre-cast cylinder liner in the relative position of the cylinder in the prior art and provides a V-shaped cylinder liner fitting positioning clamp and process method.

[0006] This patent takes a V6 cylinder as an example to introduce the innovative V-shaped cylinder liner positioning machining process. It discards the traditional cylinder liner inserting process and the machining method that uses the shape as a positioning reference. The best fitting positioning process is adopted, which uses the far end of the four cylinder liner side generatrix as the positioning point and positions the X and Y axes to minimize the positional deviation of all cylinder liners relative to the design center position, ensuring that the positional deviation of the cylinder liner is minimized to ≤φ0.5mm, which is higher than the international advanced standard of ≤φ1.0mm. This process has helped domestic high-end engines to reach international advanced levels, which has a profound significance for the development of domestic automobile engines.

[0007] It should be noted that, in this article, relational terms such as first and second and the like are used merely to distinguish one entity or action from another, without necessarily requiring or implying that there is any such actual relationship or order between them. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device.

[0008] To solve the above technical problems, the present application is realized by adopting the following technical solutions:

[0009] A V-shaped cylinder sleeve fitting positioning fixture, comprising:

[0010] Two sets of split X-axis centering positioning modules, two sets of split Y-axis centering positioning modules, Z-axis positioning points, and Z-axis auxiliary supports;

[0011] The split X-axis centering positioning module is composed of X-axis centering clamps 1 and 2, X-axis positioning points 1, 2, 3, and 4, wherein the X-axis centering clamp 1 controls the X-axis positioning points 1 and 2, and the X-axis centering clamp 2 controls the X-axis positioning points 3 and 4.

[0012] Under the synchronous pushing of the split X-axis centering positioning module, the positioning points X1 and X2 in the X-axis centering clamp 1 make the centers of the 1 and 6 cylinder holes centering positioning, and the positioning points X3 and X4 in the X-axis centering clamp 2 make the centers of the 3 and 4 cylinder holes centering positioning, so that the intersection line of the planes formed by the center lines of the two side cylinder holes is relatively coincident with the center of the fixture.

[0013] The split Y-axis centering positioning module is composed of Y-axis centering clamps 1 and 2, Y-axis positioning points 1, 2, 3, and 4, wherein the Y-axis centering clamp 1 controls the Y-axis positioning points 1 and 2, and the Y-axis centering clamp 2 controls the Y-axis positioning points 3 and 4.

[0014] Under the synchronous pushing of the split Y-axis centering positioning module, the positioning points Y1 and Y2 in the Y-axis centering clamp 1 make the centers of the 1 and 3 cylinder holes centering positioning, and the positioning points Y3 and Y4 in the Y-axis centering clamp 2 make the centers of the 4 and 6 cylinder holes centering positioning, so that the midpoint of the centers of the two side cylinder holes has the minimum deviation from the design center.

[0015] The Z-axis positioning points and Z-axis auxiliary supports form four Z-axis plane point support cylinders.

[0016] Further, the V-shaped cylinder sleeve fitting positioning fixture further comprises an anti-vibration auxiliary support and a hydraulic control system.

[0017] The anti-vibration auxiliary support is used to prevent the cylinder body from moving.

[0018] The hydraulic control system is used for X and Y direction positioning, clamping the cylinder body and pressure control.

[0019] A V-shaped cylinder sleeve fitting positioning process method, characterized in that:

[0020] The equal height points of the X-direction side busbars of the distal end 1, 3, 4, and 6 cylinder holes are used as the X-direction positioning reference, and the two sets of centering clamps are used to clamp the X-direction busbars of the 1, 6 cylinder holes and the 3, 4 cylinder holes, respectively, so that the center lines of the 1, 6 cylinder holes and the 3, 4 cylinder holes coincide with the X-direction center of the clamp center, and the two sets of centering clamps are also used to clamp the Y-direction busbars of the 1, 6 cylinder holes and the 3, 4 cylinder holes, so that the center lines of the 1, 6 cylinder holes and the 3, 4 cylinder holes have the minimum deviation from the Y-direction center of the clamp center, the X-direction wall thickness of the sleeve is uniform, and the Y-direction center of the sleeve is closer to the design center; the three-point support and one auxiliary support are used as the positioning and clamping points in the Z-direction.

[0021] Further, a V-shaped cylinder sleeve fitting positioning process method, the specific steps are as follows:

[0022] Step 1: Take two points at the left and right top surface edges of the V6 cylinder body cylinder hole as the Z-direction plane positioning points, one of which is an auxiliary support point, and place the workpiece in the positioning clamp;

[0023] Step 2: Take four equal height points on the busbars of the distal end 1, 3, 4, and 6 cylinder sleeves as the X-direction positioning points, and use the two sets of centering clamps in the centering clamping mode. Under the synchronous pushing of the centering positioning module, the positioning points X1 and X2 in the X-direction centering clamp 1 make the centers of the 1, 6 cylinder holes centering positioning, and the positioning points X3 and X4 in the X-direction centering clamp 2 make the centers of the 3, 4 cylinder holes centering positioning, so that the intersection lines of the planes formed by the center lines of the two side cylinder holes respectively coincide with the center of the clamp;

[0024] Step 3: Reduce the pressure of the X-direction centering positioning module to 0.5Mba through the hydraulic control system, and continuously control the pressure at 0.5Mba;

[0025] Step 4: As above, take four equal height points on the busbars of the distal end 1, 3, 4, and 6 cylinder sleeves as the Y-direction positioning points, also use the two sets of centering clamps in the centering clamping mode. Under the synchronous pushing of the Y-direction centering positioning module, the positioning points Y1 and Y2 in the Y-direction centering clamp 1 make the centers of the 1, 3 cylinder holes centering positioning, and the positioning points Y3 and Y4 in the Y-direction centering clamp 2 make the centers of the 4, 6 cylinder holes centering positioning, so that the center points of the centers of the two side cylinder holes have the minimum deviation from the design center;

[0026] Step 5: Reduce the pressure of the Y-direction centering positioning module to 0.5Mba through the hydraulic control system, and continuously control the pressure at 0.5Mba;

[0027] Step 6, the workpiece is pressed at Z1, Z2 and Z3 by the hydraulic control system, at this time, the workpiece is limited by four X-direction positioning points and four Y-direction positioning points in the clamp and cannot move along the X-direction and the Y-direction, but can only move slightly up and down, under the action of the pressing force at Z-direction 3, the Z-direction presents a plane state, so that the workpiece is positioned and clamped in the Z-direction;

[0028] Step 7, the workpiece is pressed after starting the Z-direction auxiliary support;

[0029] Step 8: start the anti-shock auxiliary support;

[0030] Step 9, in this posture, the workpiece is clamped in the X and Y directions; at the same time, the workpiece is initially positioned at Z-direction 3 points, X-direction 2 points and Y-direction 2 points, so that the positioning position of the workpiece cylinder sleeve and the ideal position designed by the clamp achieve the best fitting state with the minimum deviation.

[0031] Further, the X-direction centering clamp 1 controls X positioning point 1 and X positioning point 2, and the X-direction centering clamp 2 controls X positioning point 3 and X positioning point 4;

[0032] Under the synchronous pushing of the X-direction centering positioning module, the positioning points X1 and X2 in the X-direction centering clamp 1 make the centers of the 1 and 6 cylinder holes centering positioning, and the positioning points X3 and X4 in the X-direction centering clamp 2 make the centers of the 3 and 4 cylinder holes centering positioning, so that the intersection lines of the planes formed by the center lines of the two side cylinder holes respectively relatively coincide with the center of the main clamp;

[0033] The Y-direction centering clamp 1 controls Y positioning point 1 and Y positioning point 2, and the Y-direction centering clamp 2 controls Y positioning point 3 and Y positioning point 4;

[0034] Under the synchronous pushing of the Y-direction centering positioning module, the positioning points Y1 and Y2 in the Y-direction centering clamp 1 make the centers of the 1 and 3 cylinders centering positioning, and the positioning points Y3 and Y4 in the Y-direction centering clamp 2 make the centers of the 4 and 6 cylinders centering positioning, so that the midpoints of the centers of the two side cylinder holes have the minimum deviation from the design center.

[0035] Further, the support and the auxiliary support adopt a micro-unequal height design, the auxiliary support is 0.3mm lower than the Z-direction support, so as to avoid the clamping deviation of the workpiece during installation.

[0036] Further, the hydraulic control system control method comprises:

[0037] Action one: the X-direction centering positioning module clamps the workpiece inward, so that the X-direction center of the workpiece is accurate, then the pressure is reduced to 0.5Mba and is kept, which plays a role of limiting the workpiece from moving backward by the positioning point. Avoiding the movement of the workpiece along the X-direction when clamping in the Y-direction, while the workpiece can move along the Y-direction.

[0038] Action two: the Y direction centering positioning module clamps the workpiece in the middle, accurately centers the workpiece in the Y direction, and then reduces the pressure to 0.5 Mba and keeps the pressure, thereby playing a role of positioning point limiting the workpiece from moving. The workpiece can be prevented from moving along the X and Y directions when clamped in the Z direction, and the workpiece can also move downward along the Z direction.

[0039] Action three: the shockproof auxiliary support is in place, which can enhance the effect of preventing the workpiece from moving.

[0040] Action four: the Z direction main compression is compressed after the Z direction auxiliary support is in place.

[0041] Further, the Y direction clamping force needs to be between 2.5-2.7 Mba, and the workpiece installation position fitting effect is best after clamping;

[0042] When the Y direction centering positioning module is started to position and clamp, the X clamping module pressure is reduced to 0.5 Mba, at this time the Y direction clamping pressure is 2.5 Mba, and the workpiece moves a small amount along the Y direction, under the synchronous push of the Y direction centering positioning module, so that the workpiece installation Y direction center coincides with the design center of the clamp.

[0043] Further, the V-shaped cylinder body and cylinder sleeve fitting positioning process method further comprises the step 10 of machining the bottom plane of the cylinder body and machining two process pin holes on the bottom plane.

[0044] Further, the V-shaped cylinder body and cylinder sleeve fitting positioning process method further comprises the step 11 of taking the bottom surface and the two pin holes on the bottom surface as the positioning reference for processing in all subsequent processing procedures.

[0045] Compared with the prior art, the beneficial effects of the present application are:

[0046] The V-shaped cylinder body and cylinder sleeve fitting positioning clamp and process method of the present application adopts a cylinder sleeve bidirectional centering fitting positioning method, which can ensure the position degree of the cylinder sleeve and improves the traditional processing method of taking the appearance of the V-shaped cylinder body as the positioning reference. The process method respectively takes the side generatrix of the distal end cylinder hole 1, 3, 4 and 6 as the X direction positioning reference, so that the axis lines of the left and right side cylinder holes each form a plane, the intersection line of the two planes coincides with the design reference of the clamp, the uniformity of the wall thickness of the cylinder sleeve in the X direction is ensured, the Y direction adopts a centering positioning module to center the cylinder hole generatrix, the workpiece Y direction cylinder hole center is closer to the design center, and the Z direction adopts three-point positioning + one-point auxiliary support as the positioning and clamping point. The three-point positioning and auxiliary support adopt a micro-unequal height design to avoid workpiece clamping deviation. BRIEF DESCRIPTION OF DRAWINGS

[0047] The present application will be further described below in conjunction with the drawings:

[0048] Figure 1 Appearance positioning schematic diagram;

[0049] Figure 1The middle symbol means:

[0050] 1, Z1,2, Y1,3, X1,4, Z3,5, X2,6, Z4,7, Z2;

[0051] Figure 2 The structure diagram of the casting sleeve process;

[0052] Figure 3 The structure diagram of the sleeve process;

[0053] Figure 4a The schematic diagram of Z-direction positioning point Figure 1 ;

[0054] Figure 4b The schematic diagram of Z-direction positioning point Figure 2 ;

[0055] Figure 4b The middle symbol means:

[0056] 1, Z1,2,6, Z3,4, Z4,5,4, 3, Z2,8,1;

[0057] Figure 4c The cross section of No. 1 cylinder hole Figure 1 ;

[0058] Figure 4d The cross section of No. 1 cylinder hole Figure 2 ;

[0059] Figure 4d The middle symbol means:

[0060] 1, 1, 2, 6, Y2, X2, X1, Y1;

[0061] Figure 4e The cross section of No. 3 cylinder hole Figure 1 ;

[0062] Figure 4f The cross section of No. 3 cylinder hole Figure 2 ;

[0063] Figure 4f The middle symbol means:

[0064] 1, 3, 2, 4, Y4, X4, X3, Y3;

[0065] Figure 5 The schematic diagram of the fitting positioning clamp for the V-shaped cylinder sleeve Figure 1 ;

[0066] Figure 6 The schematic diagram of the fitting positioning clamp for the V-shaped cylinder sleeve Figure 2 ;

[0067] Figure 6 Meaning of symbols:

[0068] 1, Y centering clamp 1, 2, Z pressing 2, 3, Z positioning 3, 4, auxiliary support, 5, X positioning point 3, 6, X positioning point 4, 7, Z auxiliary support, 8, Z pressing 4, 9, Y centering clamp 2, 10, four-axis rotary table, 11, Z pressing 2, 12, Z positioning 3, 13, Y positioning 4, 14, Y positioning 3, 15, X positioning point 2, 16, X centering clamp 2, 17, X centering clamp 1, 18, X positioning point 1, 19, X positioning 1, 20, Y positioning 1, 21, Y positioning 2, 22, Z positioning 1, 23, Z pressing 1;

[0069] Figure 7a It is a schematic diagram of a split X centering positioning module.

[0070] Figure 7a Meaning of symbols:

[0071] 1, X positioning point 1, 2, X positioning point 2, 3, X positioning point 3, 4, X positioning point 4, 5, X centering clamp 1, 6, X centering clamp 2;

[0072] Figure 7b It is a schematic diagram of a fitting Y centering positioning module.

[0073] Figure 7b Meaning of symbols:

[0074] 1, Y positioning point 1, 2, Y positioning point 2, 3, Y positioning point 3, 4, Y positioning point 4, 5, Y centering clamp 1, 6, Y centering clamp 2;

[0075] Figure 7c It is a schematic diagram of an X, Y compact positioning module.

[0076] Figure 7c Meaning of symbols:

[0077] 1, cylinder sleeve, 2, 3 cylinder, 3, Y2, 4, X3, 5, X4, 6, Y4, 7, 4 cylinder, 8, cylinder sleeve, 9, cylinder sleeve, 10, 6 cylinder, 11, Y3, 12, X2, 13, X1, 14, Y1, 15, 1 cylinder, 16, cylinder sleeve;

[0078] Figure 8 It is a schematic diagram of auxiliary support Z height.

[0079] Figure 8 Meaning of symbols:

[0080] 1, Z1, 2, Z2, 3, Z3, 4, Z auxiliary support. DETAILED DESCRIPTION

[0081] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings of the embodiments of the present application. In the drawings, the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0082] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0083] The present application will be described in detail below with reference to the drawings:

[0084] The present application provides an embodiment, a V-shaped cylinder sleeve fitting positioning clamp, comprising 2 sets of X-direction center positioning modules, 2 sets of Y-direction center positioning modules, Z-direction positioning points, Z-direction auxiliary supports, anti-shock auxiliary supports, pressing units, hydraulic control systems and the like main components.

[0085] The anti-shock auxiliary support is used to prevent the cylinder from moving;

[0086] The pressing unit and the hydraulic control system are used to clamp the cylinder in the X and Y directions.

[0087] The fitting clamp is a positioning method of the clamp using fitting method; the split X-direction center positioning module is 2 sets of X-direction center positioning modules using separate control; the compact X and Y direction positioning point structure design is to design the X direction positioning point and the Y direction positioning point in one cylinder hole by using narrow space, which has great design difficulty.

[0088] This invention provides another embodiment of a V-type cylinder block cylinder liner fitting and positioning process. This method employs the optimal fitting and positioning process for the maximum solid mass of the cylinder liner, minimizing the deviation between the maximum solid mass centers of the six cylinder liners and the ideal design centers. This ensures that the machined cylinder liners are positioned optimally, with uniform wall thickness, thus eliminating problems such as increased fuel consumption, cylinder scoring, cylinder detonation, and reduced engine life. In the following text, the V6 cylinder block is referred to as the workpiece. See also... Figure 1 , Figure 2 , Figure 3 , Figure 4a , Figure 4b , Figure 4c , Figure 4d , Figure 4e , Figure 4f , Figure 5 , Figure 6 , Figure 7a , Figure 7b , Figure 7c , Figure 8 .

[0089] This process uses the same height of the X-direction generatrix of the distal cylinder bores (cylinders 1, 3, 4, and 6) as the X-direction positioning reference. Two sets of centering clamps clamp the X-direction generatrix of cylinder bores 1 and 6, and cylinder bores 3 and 4, respectively, aligning the centerlines of cylinder bores 1 and 6, and cylinder bores 3 and 4 with the X-direction center of the fixture. Two additional sets of centering clamps also clamp the Y-direction generatrix of cylinder bores 1 and 6, and cylinder bores 3 and 4, minimizing the deviation between the centerlines of cylinder bores 1 and 6, and cylinder bores 3 and 4 and the Y-direction center of the fixture. This ensures consistent cylinder liner wall thickness in the X-direction (left-right direction) and brings the cylinder liner center in the Y-direction (front-back direction) closer to the design center. In the Z-direction, three-point support plus one auxiliary support are used for positioning and clamping. The support and auxiliary support feature a slightly unequal height design, with the auxiliary support 0.3mm lower than the Z-direction support to prevent workpiece misalignment during installation. The compact design of the X and Y positioning points solves the structural design challenge of simultaneously arranging two sets of centering modules in a confined space. The X and Y positioning point structure design in confined spaces solves the challenges of fixture structure design. The micro-dimensional adjustment function of the X and Y alignment module positioning points results in higher fixture positioning accuracy.

[0090] Non-standard aligning clamps require a large aligning clamping stroke to meet fixture design requirements; conventional clamps with smaller strokes cannot meet these needs. The large stroke design of the X-axis aligning clamp solves interference avoidance during blank clamping, providing a larger workpiece clamping space and facilitating operation. This invention's X-axis aligning positioning and clamping structure ensures that the workpiece centerline coincides with the fixture centerline in the X-axis direction. The Y-axis fitting aligning positioning and clamping structure ensures the workpiece center reaches the optimal position. The Z-axis planar four-point unequal height design prevents workpiece misalignment due to incorrect operation. The hydraulic control system's pressure control design provides both limit function and allows movement in unrestricted directions.

[0091] V6 Cylinder Block Positioning Process Description:

[0092] 1) Each positioning point in X and Y has a size adjustment function, which can adjust the thickness of the shims and the height of the positioning points, thereby reducing the manufacturing and assembly precision of the centering positioning module and saving manufacturing costs.

[0093] 2) Fitting-type X-axis centering clamp module for centering and positioning

[0094] The split-type X-axis alignment positioning module consists of X-axis alignment clamp 1, X-axis alignment clamp 2, X positioning point 1, X positioning point 2, X positioning point 3, and X positioning point 4. X-axis alignment clamp 1 controls X positioning point 1 and X positioning point 2, and X-axis alignment clamp 2 controls X positioning point 3 and X positioning point 4.

[0095] Under the synchronous push of the X-axis centering positioning module, the positioning points X1 and X2 in X-axis centering clamp 1 center the centers of cylinder bores 1 and 6, and the positioning points X3 and X4 in X-axis centering clamp 2 center the centers of cylinder bores 3 and 4, so that the intersection line of the planes formed by the center lines of the cylinder bores on both sides coincides with the center line of the spindle bore.

[0096] 3) The split Y-axis alignment positioning module consists of Y-axis alignment clamp 1, Y-axis alignment clamp 2, Y positioning point 1, Y positioning point 2, Y positioning point 3, and Y positioning point 4. Y-axis alignment clamp 1 controls Y positioning point 1 and Y positioning point 2, and Y-axis alignment clamp 2 controls Y positioning point 3 and Y positioning point 4.

[0097] Under the synchronous push of the Y-axis centering positioning module, positioning points Y1 and Y2 in Y-axis centering clamp 1 center the centers of cylinders 1 and 3, while positioning points Y3 and Y4 in Y-axis centering clamp 2 center the centers of cylinders 4 and 6, achieving minimal deviation between the midpoint of the cylinder bore centers on both sides and the design center. The Y-axis clamping force needs to be between 2.5 and 2.7 MPa for optimal workpiece mounting position fitting after clamping.

[0098] When the Y-axis centering positioning module is activated for positioning and clamping, the pressure of the X-clamp module has dropped to 0.5 Mba, and the Y-axis clamping pressure is 2.5 Mba. The workpiece can be displaced slightly along the Y-axis. Under the synchronous push of the Y-axis centering positioning module, the Y-axis center of the workpiece is made to coincide with the design center of the fixture.

[0099] 4) The structural design of arranging X and Y positioning points in a single cylinder bore simultaneously enables the narrow cylinder bore space to have both X and Y positioning functions, thus solving the design difficulties caused by limited space.

[0100] 5) The auxiliary support design with unequal height in the Z direction has three positioning points (Z1 / Z2 / Z3) at the same height. The height of the auxiliary support in the Z direction is slightly lower than that of the main support by 0.3mm. This can prevent over-positioning of the four points on the plane and avoid large offset of the workpiece in the Z direction, which would cause workpiece clamping error due to the deviation between the center of gravity of the cylinder and the center of gravity of the support.

[0101] 6) Hydraulic control principle:

[0102] Action 1: The X-axis centering module clamps the workpiece inward to ensure accurate X-axis centering. Then, the pressure is reduced to 0.5 MPa and maintained, acting as a positioning point to prevent the workpiece from moving backward. This prevents the workpiece from moving along the X-axis while simultaneously allowing it to move along the Y-axis during Y-axis clamping.

[0103] Action 2: The Y-axis centering module clamps the workpiece in the center, ensuring accurate Y-axis centering. Then, the pressure is reduced to 0.5 MPa and maintained, acting as a positioning point to prevent workpiece movement. This prevents the workpiece from moving along the X and Y axes during Z-axis clamping, while allowing it to move downwards along the Z-axis.

[0104] Action 3: The anti-vibration auxiliary support is in place, which can enhance the function of preventing the workpiece from moving.

[0105] Action 4: Tighten the Z-axis main clamp, and tighten the Z-axis auxiliary support after it is in place.

[0106] A method for fitting and positioning cylinder liners in a V-shaped cylinder block, the specific steps of which are as follows:

[0107] Step 1: Take two points on each of the left and right top edges of the cylinder bore of the V6 cylinder block as Z-axis plane positioning points, one of which is an auxiliary support point, and place the workpiece in the fixture;

[0108] Step 2: Take four points of equal height on the far end cylinder liner (cylinders 1, 3, 4, and 6) as X-direction positioning points. Use two sets of centering clamps to clamp the cylinders in a centering manner. Under the synchronous push of the centering positioning module, positioning points X1 and X2 in X-direction centering clamp 1 center the centers of cylinder 1 and 6, and positioning points X3 and X4 in X-direction centering clamp 2 center the centers of cylinder 3 and 4, so that the intersection line of the planes formed by the center lines of the cylinder holes on both sides coincides with the center of the clamp.

[0109] Step 3: Reduce the pressure of the X-axis centering module to 0.5 MPa using the hydraulic control system; and maintain the pressure at 0.5 MPa.

[0110] Step 4: Following the same procedure, take four points of equal height on the far-end cylinder liner (cylinders 1, 3, 4, and 6) as Y-axis positioning points. Use two sets of centering clamps for centering. Under the synchronous push of the Y-axis centering positioning module, positioning points Y1 and Y2 in Y-axis centering clamp 1 center the centers of cylinders 1 and 3, while positioning points Y3 and Y4 in Y-axis centering clamp 2 center the centers of cylinders 4 and 6, minimizing the deviation between the midpoint of the cylinder bore centers and the design center. The Y-axis clamping force should be between 2.5 and 2.7 MPa for optimal workpiece mounting position fitting after clamping.

[0111] When the Y-axis centering positioning module is activated for positioning and clamping, the pressure of the X-clamp module has dropped to 0.5 Mba, and the Y-axis clamping pressure is 2.5 Mba. The workpiece can be displaced slightly along the Y-axis. Under the synchronous push of the Y-axis centering positioning module, the Y-axis center of the workpiece is made to coincide with the design center of the fixture.

[0112] Step 5: Reduce the pressure of the Y-axis centering module to 0.5 MPa using the hydraulic control system, and maintain the pressure at 0.5 MPa.

[0113] Step 6: The workpiece is clamped at Z1, Z2 and Z3 by the hydraulic control system. At this time, the workpiece is limited by 4 X-axis positioning points and 4 Y-axis positioning points in the fixture. It cannot move along the X and Y directions, but can only move up and down slightly. Under the action of the clamping force at Z3, the Z direction is in a plane state, so that the workpiece is positioned and clamped in the Z direction.

[0114] Step 7: After activating the Z-axis auxiliary support, clamp the workpiece;

[0115] Step 8: Activate seismic auxiliary supports;

[0116] Step 9: Clamp the workpiece in the X and Y directions under this posture. At the same time, perform initial workpiece positioning at 3 points in the Z direction, 2 points in the X direction, and 2 points in the Y direction, so that the workpiece cylinder liner positioning position achieves the best fit with the ideal position designed by the fixture, with minimal deviation.

[0117] Step 10: Machin the bottom plane of the cylinder block and machine two process pin holes on the bottom plane;

[0118] Step 11: All subsequent machining processes are performed using the bottom surface and the two pin holes on the bottom surface as positioning references.

[0119] After machining, the cylinder liner has a uniform wall thickness, close to the ideal position effect, and meets the technical requirement of position accuracy within ≤0.5mm.

[0120] The process method for maximum solid fit of cylinder liners achieves the effect of minimizing the deviation between the six cylinder liner positions and the fixture design center;

[0121] The design of arranging two sets of aligning positioning points in different directions within a small cylinder bore space solves the problem of positioning point arrangement design.

[0122] In addition, this process can be implemented in a variety of processing equipment, such as vertical machining centers, horizontal machining centers, and cradle machining centers, offering advantages such as strong equipment selection and stable process.

[0123] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be included within the scope of protection of the present invention. Furthermore, all content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A V-block cylinder liner fitting positioning fixture, characterized by, It comprises: Two sets of split X-direction centering positioning modules, two sets of split Y-direction centering positioning modules, Z-direction positioning points, and Z-direction auxiliary supports; The split X-direction centering positioning module is composed of X-direction centering clamps 1 and 2, X-direction positioning points 1, 2, 3, and 4. The X-direction centering clamp 1 controls the X-direction positioning points 1 and 2, and the X-direction centering clamp 2 controls the X-direction positioning points 3 and 4. The equal-height points of the X-direction side busbars of the distal ends 1, 3, 4, and 6 cylinders are used as the X-direction positioning reference. Two sets of X-direction centering clamps clamp the X-direction busbars of the 1 and 6 cylinder bores and the 3 and 4 cylinder bores, respectively. Under the synchronous pushing of the split X-direction centering positioning module, the X-direction positioning points 1 and 2 in the X-direction centering clamp 1 center the 1 and 6 cylinder bores, and the X-direction positioning points 3 and 4 in the X-direction centering clamp 2 center the 3 and 4 cylinder bores, so that the intersection of the planes formed by the center lines of the two sets of cylinder bores coincides with the center of the clamp. The split Y-direction centering positioning module is composed of Y-direction centering clamps 1 and 2, Y-direction positioning points 1, 2, 3, and 4. The Y-direction centering clamp 1 controls the Y-direction positioning points 1 and 2, and the Y-direction centering clamp 2 controls the Y-direction positioning points 3 and 4. Four equal-height points on the Y-direction busbars of the distal ends 1, 3, 4, and 6 cylinders are used as the Y-direction positioning points. Two sets of Y-direction centering clamps clamp the Y-direction busbars of the 1 and 6 cylinder bores and the 3 and 4 cylinder bores, respectively. Under the synchronous pushing of the split Y-direction centering positioning module, the Y-direction positioning points 1 and 2 in the Y-direction centering clamp 1 center the 1 and 3 cylinder bores, and the Y-direction positioning points 3 and 4 in the Y-direction centering clamp 2 center the 4 and 6 cylinder bores, so that the midpoint of the centers of the two sets of cylinder bores deviates the least from the design center. The Z-direction uses three Z-direction support points and one Z-direction auxiliary support point as the positioning and clamping points, forming four Z-direction plane positioning point supports for the cylinder.

2. The V-cylinder liner fitting positioning fixture according to claim 1, characterized in that: It also includes an anti-shock auxiliary support and a hydraulic control system. The anti-shock auxiliary support is used to prevent the cylinder from moving. The hydraulic control system is used to control the X and Y direction positioning, clamping of the cylinder, and pressure control.

3. The positioning process method of the V-type cylinder liner fitting positioning clamp according to claim 1, characterized in that, The specific steps are as follows: Step 1: Take two points on the left and right top surface edges of the V6 cylinder bore as Z-direction plane positioning points. Three of them are Z-direction support points, and the other one is a Z-direction auxiliary support point. Place the workpiece in the positioning clamp. Step 2: Take four equal-height points on the Y-direction busbars of the distal ends 1, 3, 4, and 6 cylinders as X-direction positioning points. Use two sets of X-direction centering clamps for centering clamping. Under the synchronous pushing of the X-direction centering positioning module, the X-direction positioning points 1 and 2 in the X-direction centering clamp 1 center the 1 and 6 cylinder bores, and the X-direction positioning points 3 and 4 in the X-direction centering clamp 2 center the 3 and 4 cylinder bores, so that the intersection of the planes formed by the center lines of the two sets of cylinder bores coincides with the center of the clamp. Step 3: Reduce the pressure of the X-direction centering positioning module to 0.5 Mba through the hydraulic control system and continuously control it at 0.5 Mba. Step 4, the same as above, take the equal height 4 points on the Y direction positioning points of the remote 1, 3, 4, 6 cylinder sleeve generatrix, also use 2 sets of Y direction centering clamps to center and clamp, under the synchronous pushing of the Y direction centering positioning module, Y positioning point 1 and Y positioning point 2 in Y direction centering clamp 1 make the 1, 3 cylinder hole centers centering positioning, Y positioning point 3 and Y positioning point 4 in Y direction centering clamp 2 make the 4, 6 cylinder hole centers centering positioning, so as to make the midpoint of the two side cylinder hole centers and the design center deviation minimum; Step 5, through the hydraulic control system, the pressure of the Y direction centering positioning module is reduced to 0.5Mba, and the pressure is continuously controlled at 0.5Mba; Step 6, through the hydraulic control system, the workpiece is pressed at the three Z direction supporting points, at this time, the workpiece is limited by 4 X positioning points and 4 Y positioning points in the clamp and cannot move along the X and Y directions, but can only move up and down by a small amount, under the action of the Z direction 3 pressing force, the Z direction is in a plane state, so as to make the workpiece Z direction positioning and clamping; Step 7, start the Z direction auxiliary supporting point to press the workpiece; Step 8: start the anti-shock auxiliary support; Step 9, in this posture, clamp the workpiece in X and Y directions; make the workpiece cylinder sleeve positioning position and the ideal position of the clamp design reach the best fitting state, with minimum deviation.

4. The positioning process method according to claim 3, characterized in that: The Z direction supporting point and the Z direction auxiliary supporting point adopt a small amount of unequal height design, the Z direction auxiliary supporting point is lower than the Z direction supporting point by 0.3mm, so as to avoid the workpiece installation deviation.

5. The positioning process of claim 3, wherein, The hydraulic control system control method comprises: Action one: the X direction centering positioning module clamps the workpiece inward, so as to make the workpiece X direction center accurate, then the pressure is reduced to 0.5Mba and the pressure is kept, so as to limit the workpiece from moving backward by the positioning point; avoid the workpiece moving along the X direction when clamping in Y direction, while the workpiece can move along the Y direction; Action two: the Y direction centering positioning module clamps the workpiece, so as to make the workpiece Y direction center accurate, then the pressure is reduced to 0.5Mba and the pressure is kept, so as to limit the workpiece from moving; avoid the workpiece moving along the X and Y directions when clamping in Z direction, while the workpiece can move downward along the Z direction; Action three: the anti-shock auxiliary support is in place, which can strengthen the prevention of workpiece movement; Action four: the Z direction main pressing is pressed, and the Z direction auxiliary supporting point is in place, so as to realize the Z direction pressing.

6. The positioning process method according to claim 3, characterized in that: The Y direction clamping force needs to be between 2.5-2.7Mba, and the workpiece installation position fitting effect is best after clamping; When starting the Y direction centering positioning module to position and clamp, the X direction centering positioning module pressure is reduced to 0.5Mba, at this time, the Y direction centering positioning module clamping pressure is 2.5Mba, the workpiece moves a small amount along the Y direction, under the synchronous pushing of the Y direction centering positioning module, so as to make the workpiece installation Y direction center coincide with the design center of the clamp.

7. The positioning process method according to claim 3, characterized in that: It further comprises step 10, machining the cylinder body bottom plane and 2 process pin holes on the bottom plane.

8. The positioning process of claim 3, wherein: It further comprises step 11, all subsequent machining processes are machined based on the bottom surface and the two pin holes on the bottom surface as the positioning reference.

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