Machining method for circumferential holes in narrow space of high-power internal combustion engine body

Abstract

The invention discloses a machining method for circumferential holes in a narrow space of a high-power internal combustion engine body, and belongs to the technical field of numerical control machine tool machining. S2, designing and manufacturing an accessory head and a cutter; the non-standard angle accessory head and the cutter can penetrate into a narrow space of a machine body; s3, a machining program is compiled according to the circumferential holes to be machined in the narrow space; and S4, the numerical control machine tool is started, and machining is conducted according to the programmed machining program. The side wall hole in the narrow space of the workpiece can be machined, the machining method is simple and low in cost, remarkable technical advantages and economic benefits are achieved, the machining requirements of workpieces of complex structures are met, and wide application prospects are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of numerical control machine tool processing, and specifically relates to a method for machining circumferential holes in a narrow space of a high-power internal combustion engine body. Background Art

[0002] The holes in a high-power internal combustion engine are sometimes in a narrow space, and ordinary cutting tools such as drills are difficult to operate in this narrow space, making it difficult to machine the holes. For example, the circumferential holes on the inner wall of the piston cylinder, where the space in the piston cylinder is narrow. During the numerical control machine tool processing, various workpieces with complex structures are often encountered. With traditional processing methods, the circumferential holes often have low processing efficiency or the processing quality does not meet the process requirements due to space limitations, tool limitations, or insufficient machining accuracy. Summary of the Invention

[0003] In order to overcome the deficiencies in the background art, the present invention provides a method for machining circumferential holes in a narrow space of a high-power internal combustion engine body, aiming to reduce the space occupied during machining, improve machining accuracy and efficiency, and reduce machining costs.

[0004] To achieve the above object, the present invention provides the following technical solution: A method for machining circumferential holes in a narrow space of a high-power internal combustion engine body, comprising the following steps:

[0005] S1: Positioning and installing the body; Use a fixture to stably clamp the body on the workbench of the numerical control machine tool, and use the precision positioning system of the numerical control machine tool to accurately position the body;

[0006] S2: Setting of the cutting tool; Design and manufacture an accessory head and a cutting tool; Install the cutting tool on the spindle of the non-standard angle accessory head of the numerical control machine tool, so that the non-standard angle accessory head together with the cutting tool can penetrate into the narrow space of the body;

[0007] S3: Programming the machining procedure; Program the machining procedure according to the circumferential holes to be machined in the narrow space; The program includes tool path planning, machining parameter setting, and cutting speed of the cutting tool;

[0008] S4: Implementing the machining; Start the numerical control machine tool and perform machining according to the programmed machining procedure; After machining is completed, clean and inspect the body to ensure that the dimensions, shapes, and position accuracies of the circumferential holes at different angles in the narrow space meet the process requirements.

[0009] As a further optimization, in the step S3, a simulation verification step is further included, specifically, after the machining procedure is programmed, the machining procedure is simulated and verified to verify the correctness and feasibility of the program.

[0010] As a further optimization, in step S4, a trial machining step is further included. Specifically, after starting the CNC machine tool, trial machining is first carried out. During the trial machining process, closely monitor the tool state, the change of cutting force, and the surface quality of the machine body. If there are problems during the trial machining process, adjust the machining parameters in a timely manner to ensure machining accuracy and efficiency; if there are no problems during the trial machining process, continue the machining until the machining is completed.

[0011] As a further optimization, in step S1, before installing the machine body, fixture installation steps S101 - S105 are further included;

[0012] S101: Grind the workbench surface of the machine tool with an oilstone, and wipe the workbench surface and the lower plane of the fixture with a cotton yarn to ensure that the plane is flat, clean, and has no high points;

[0013] S102: Place the fixture along the X direction of the machine tool on the workbench surface of the machine tool, and make the inclined plane of the fixture face the side where the machine tool control panel is located;

[0014] S103: Adsorb the dial indicator on the spindle of the CNC machine tool, and straighten the fixture along the X direction of the machine tool according to the alignment reference surface of the fixture, ensuring that the error does not exceed 0.01 mm;

[0015] S104: Use the dial indicator to align the upper surfaces of the vertical positioning blocks of the fixture, ensuring that the reading difference during the alignment process is within the range of 0.01 mm. Otherwise, place copper sheets with appropriate thickness under the corresponding vertical positioning blocks of the fixture until the reading difference meets the requirement within the range of 0.01 mm;

[0016] S105: On the premise that both steps S103 and S104 are satisfied, press the fixture onto the machine tool workbench with a clamp.

[0017] As a further optimization, the machine body installation method in step S1 includes steps S111 - S118;

[0018] S111: Wipe the main positioning reference surface of the fixture and the surfaces of the vertical positioning blocks;

[0019] S112: Carefully insert two process mandrels into the spindle holes of the machine body from both ends of the machine body respectively, then use a crane to lift the machine body with the oil pan surface facing down at an angle of 45°, blow the iron chips and dirt on the surface and inner cavity of the machine body with an air gun, remove the burrs on the oil pan surface of the machine body with an oilstone, and then wipe it clean with a cotton yarn;

[0020] S113: Hoist the machine body with the oil pan surface facing the main positioning reference surface direction of the fixture, and slowly lower it so that the oil pan surface fits onto the main positioning reference surface of the fixture. At the same time, make the outer cylindrical surfaces of the two process mandrels respectively rest on the vertical positioning blocks at both ends of the fixture;

[0021] S114: Rotate the stud of the clamp's tightening device to slowly move the machine body until the end face of the flywheel fits into the end face positioning block of the clamp;

[0022] S115: Use an adjustable wrench to pre-tighten the nuts of the upper clamping plate, and then pre-tighten the nuts of the lower clamping plate;

[0023] S116: Use a 0.02mm feeler gauge to check the fit between the oil pan surface of the engine body and the main positioning reference surface of the fixture, the process mandrel and the vertical positioning block of the fixture, and the end face of the flywheel of the engine body and the end face positioning block of the fixture. If unqualified, repeat steps S114-S115 until positioning and pre-tightening are completed;

[0024] S117: Use a torque wrench to tighten the nuts of the upper clamp plate, and then tighten the nuts of the lower clamp plate;

[0025] S118: Use a 0.02mm feeler gauge again to check the positioning and clamping of the machine body according to the requirements of step S116.

[0026] As a further optimization, the specific processing method for the machine body in step S4 includes steps S401-S405;

[0027] S401: Replace and install the preset non-standard angle attachment head on the CNC machine tool;

[0028] S402: According to the circumferential hole to be processed, the corresponding tool is installed on the non-standard angle attachment head;

[0029] S403: starting the CNC machine tool, the tool starts to rotate, and according to the preset planning path of the machining program, the non-standard angle attachment head moves down together with the tool into the narrow space of the machine body, stops moving down after reaching the axial plane of the circumferential hole, and then according to the preset planning path of the machining program, the non-standard angle attachment head rotates until the tool is aligned with the position of the circumferential hole to be machined, and then the non-standard angle attachment head and the tool translate toward the position of the circumferential hole until the machining of the circumferential hole is completed;

[0030] S404: After the circumferential hole processing of step S403 is completed, according to the preset planning path of the processing program, the non-standard angle attachment head is first translated to make the tool leave the circumferential hole, and then the non-standard angle attachment head is moved up to make the tool leave the narrow space of the machine body, and then the CNC machine tool is stopped and the tool stops rotating; according to the next circumferential hole to be processed, the corresponding tool is replaced;

[0031] S405: Repeat steps S403-S404 until all the circumferential holes are processed.

[0032] In summary, the present invention can machine the side wall holes in the narrow space of the workpiece. The machining method is simple and low in cost, with significant technical advantages and economic benefits. It meets the machining requirements of workpieces with complex structures and has broad application prospects. Description of the Drawings

[0033] Figure 1 It is a schematic flowchart of the method according to an embodiment of the present invention;

[0034] Figure 2 It is a schematic structural diagram of the tool in the piston cylinder during machining according to an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the position of the circumferential holes on the inner wall of the piston cylinder according to an embodiment of the present invention.

[0036] In the figure: 1 represents the accessory head; 2 represents the tool; 3 represents the circumferential hole; 4 represents the piston cylinder. Detailed Embodiments

[0037] Next, with reference to the drawings of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some preferred embodiments of the present invention, rather than all embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0038] Embodiment; Please refer to Figure 1 、 2 、3.

[0039] In this embodiment, taking the circumferential holes 3 on the inner wall of the piston cylinder 4 of a high-power internal combustion engine as the machining object, the following technical solution is provided: A method for machining circumferential holes in the narrow space of the body of a high-power internal combustion engine, including the following steps:

[0040] S1: Positioning and installing the body; Use a fixture to stably clamp the body on the workbench of the numerical control machine tool, and use the precision positioning system of the numerical control machine tool to accurately position the body; thereby enabling the numerical control machine tool to obtain the position coordinates of the circumferential holes 3 to be machined.

[0041] S2: Setting of the tool 2; Design and manufacture the accessory head 1 and the tool 2; Install the tool 2 on the spindle of the non-standard angle accessory head 1 of the numerical control machine tool, so that the non-standard angle accessory head 1 together with the tool 2 can penetrate into the narrow space of the body; At this time, according to the dimensions, shapes and machining requirements of the circumferential holes 3 at different angles in the narrow space, design and manufacture the accessory connection and the tool 2. Occupy the space to the minimum extent as much as possible, directly connect the clamping device to the accessory, and reduce the thickness and turning radius of the accessory. The tool 2 is made of high-strength and high-rigidity materials, and the structure of the tool 2 should be compact to adapt to the machining requirements of the narrow space.

[0042] S3: Programming of machining procedures; programming machining procedures according to the circumferential holes 3 to be machined in a narrow space; the procedures include tool path planning, machining parameter setting, and cutting speed of the tool 2; at this time, machining procedures are programmed according to the machining process requirements of circumferential holes 3 at different angles in a narrow space. The procedures include tool path planning, machining parameter setting, cutting speed control, etc. Simulate and verify the correctness and feasibility of the procedures through simulation.

[0043] S4: Machining implementation; start the CNC machine tool and perform machining according to the programmed machining procedures; after machining is completed, clean and inspect the machine body to ensure that the dimensions, shapes, and position accuracies of the circumferential holes 3 at different angles in the narrow space meet the process requirements.

[0044] Among them, the specific machining method in step S4 includes steps S401 - S405;

[0045] S401: Replace and install a preset non-standard angle attachment head 1 on the CNC machine tool;

[0046] S402: Install the corresponding tool 2 on the non-standard angle attachment head 1 according to the circumferential hole 3 to be machined;

[0047] S403: Start the CNC machine tool, the tool 2 starts to rotate, and according to the planned path preset in the machining procedure, the non-standard angle attachment head 1 together with the tool 2 moves down into the narrow space of the machine body, stops moving down after reaching the axial plane of the circumferential hole 3, and then according to the planned path preset in the machining procedure, the non-standard angle attachment head 1 rotates until the tool 2 is aligned with the position of the circumferential hole 3 to be machined, and then the non-standard angle attachment head 1 together with the tool 2 translates towards the position of the circumferential hole 3 until the machining of this circumferential hole 3 is completed;

[0048] S404: After the machining of the circumferential hole 3 in step S403 is completed, according to the planned path preset in the machining procedure, the non-standard angle attachment head 1 first translates to make the tool 2 disengage from this circumferential hole 3, then the non-standard angle attachment head 1 moves up to make the tool 2 disengage from the narrow space of the machine body, and then stop the CNC machine tool and the tool 2 stops rotating; replace the corresponding tool 2 according to the next circumferential hole 3 to be machined;

[0049] S405: Repeat steps S403 - S404 until the machining of all circumferential holes 3 is completed.

[0050] Among them, the specific cleaning and inspection steps in step S4 are carried out between steps S403 - S404. After ensuring that each machined circumferential hole 3 is qualified through inspection, the machining of the next circumferential hole 3 is carried out.

[0051] Preferably, in step S4, a trial machining step is further included. Specifically, after starting the CNC machine tool, trial machining is first performed. During the trial machining process, closely monitor the state of the tool 2, the change of cutting force, and the surface quality of the machine body. If there are problems during the trial machining process, adjust the machining parameters in a timely manner to ensure machining accuracy and efficiency; if there are no problems during the trial machining process, continue machining until the machining is completed. To overcome the uncertainties such as the clamping of the machine body, the program setting, and the wear of the tool 2, and ensure the machining quality.

[0052] During specific implementation, to ensure the reliable installation and accurate positioning of the fixture. In step S1, before installing the machine body, a fixture installation step S101 - S105 is further included;

[0053] S101: Use an oilstone to polish the workbench surface of the machine tool, and wipe the workbench surface and the lower plane of the fixture with a cotton yarn to ensure that the plane is flat, clean, and has no high points;

[0054] S102: Place the fixture along the X - direction of the machine tool on the workbench surface of the machine tool, and make the inclined plane of the fixture face the side where the machine tool control panel is located;

[0055] S103: Adsorb the dial indicator on the spindle of the CNC machine tool, and straighten the fixture along the X - direction of the machine tool according to the alignment reference surface of the fixture, ensuring that the error does not exceed 0.01 mm;

[0056] S104: Use the dial indicator to align the upper surfaces of the vertical positioning blocks of the fixture, ensuring that the reading difference during the alignment process is within the range of 0.01 mm. Otherwise, place copper sheets with appropriate thickness under the corresponding vertical positioning blocks of the fixture until the above requirements are met;

[0057] S105: On the premise that both steps S103 and S104 are satisfied, press the fixture onto the machine tool workbench with a pressing plate.

[0058] During specific implementation, to ensure the reliable installation and installation accuracy of the machine body. The machine body installation method in step S1 includes steps S111 - S118;

[0059] S111: Wipe clean the main positioning reference surface of the fixture and the surfaces of the vertical positioning blocks;

[0060] S112: Carefully insert two process mandrels into the spindle holes of the machine body from both ends of the machine body respectively, then use a crane to lift the machine body with the oil pan surface facing down at an angle of 45°, use an air gun to blow clean the iron chips and dirt on the surface and inside cavity of the machine body, use an oilstone to remove the burrs on the oil pan surface of the machine body, and then wipe it clean with a cotton yarn;

[0061] S113: Lift and install the machine body with the oil pan surface facing the direction of the main positioning reference surface of the fixture, slowly lower it, so that the oil pan surface fits onto the main positioning reference surface of the fixture. At the same time, make the outer cylindrical surfaces of the two process mandrels respectively rest on the vertical positioning blocks at both ends of the fixture;

[0062] S114: Rotate the stud of the tightening device of the rotary fixture to slowly move the machine body until the end face of the flywheel fits against the positioning block on the end face of the fixture;

[0063] S115: Use a movable wrench to pre-tighten the nut of the upper row of pressing plates on the fixture, and then pre-tighten the nut of the lower row of pressing plates on the fixture;

[0064] S116: Use a 0.02 mm feeler gauge to check the fitting conditions between the oil pan surface of the machine body and the main positioning reference surface of the fixture, between the process mandrel and the vertical positioning block of the fixture, and between the end face of the flywheel of the machine body and the positioning block on the end face of the fixture. If it is unqualified, repeat steps S114 - S115 until positioning and pre-tightening are completed;

[0065] S117: Use a torque wrench to tighten the nut of the upper row of pressing plates on the fixture, and then tighten the nut of the lower row of pressing plates on the fixture;

[0066] S118: Use a 0.02 mm feeler gauge again to check the positioning and clamping conditions of the machine body according to the requirements of step S116.

[0067] The method of the present invention can effectively machine the side wall holes of the piston cylinder 4; of course, it can also machine the side wall holes in the narrow space of similar workpieces. The machining method is simple and the cost is low, with significant technical advantages and economic benefits, adapting to the machining requirements of workpieces with complex structures and having broad application prospects.

[0068] The parts not detailed in the present invention are prior art; for those of ordinary skill in the art, the technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body, characterized in that: The following steps are involved: S1: Positioning and installation of the machine body: Use a fixture to stably clamp the machine body on the workbench of the CNC machine tool, and use the precise positioning system of the CNC machine tool to accurately position the machine body; S2: Setting of the tool (2); designing and manufacturing the accessory head (1) and the tool (2); installing the tool (2) on the spindle of the non-standard angle accessory head (1) of the CNC machine tool, so that the non-standard angle accessory head (1) together with the tool (2) can penetrate into the narrow space of the machine body; S3: Processing program preparation; preparing a processing program according to the circular hole (3) to be processed in the narrow space; the processing program includes tool (2) path planning, processing parameter setting, and tool (2) cutting speed; S4: Processing implementation; starting the CNC machine tool and performing processing according to the programmed processing program; after the processing is completed, cleaning and inspecting the machine body to ensure that the size, shape and position accuracy of the circular holes (3) at different angles in the narrow space meet the process requirements.

2. A method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body according to claim 1, characterized in that: The step S3 also includes a simulation verification step, which is to simulate the machining program after the machining program is compiled to verify the correctness and feasibility of the program.

3. The method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body according to claim 1, characterized in that: The step S4 also includes a trial processing step, specifically, after starting the CNC machine tool, firstly performing trial processing, during which the state of the tool (2), the change in cutting force and the surface quality of the machine body are closely monitored; if there are any problems during the trial processing, the processing parameters are adjusted in time to ensure the processing accuracy and efficiency; if there are no problems during the trial processing, the processing is continued until the processing is completed.

4. A method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body according to claim 1, characterized in that: In step S1, before the machine body is installed, it also includes the fixture installation steps S101-S105; S101: Use oilstone to polish the machine tool work surface, and use cotton yarn to clean the work surface and the plane under the fixture to ensure that the surface is flat, clean and has no high spots; S102: placing the fixture on the machine tool work surface along the X direction of the machine tool, with the inclined surface of the fixture facing the side where the machine tool control panel is located; S103: adsorb the indicator on the spindle of the CNC machine tool, straighten the fixture along the X direction of the machine tool according to the fixture alignment reference surface, and ensure that the error does not exceed 0.01mm; S104: Use an indicator to align the upper surfaces of the vertical positioning blocks of the fixture to ensure that the reading difference is within the range of 0.01 mm during the alignment process; otherwise, place a copper sheet of appropriate thickness under the corresponding vertical positioning block of the fixture until the reading difference is within the range of 0.01 mm; S105: On the premise that steps S103 and S104 are satisfied, the fixture is pressed onto the machine tool workbench with a pressing plate.

5. A method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body according to claim 4, characterized in that: The machine body installation method in step S1 includes steps S111-S118; S111: Clean the main positioning reference surface of the fixture and the surface of the vertical positioning block; S112: Carefully insert the two process mandrels into the main shaft holes of the machine body from both ends of the machine body, and then use a crane to lift the machine body oil pan with the face downward at 45 degrees, use an air gun to blow away the iron filings and dirt on the surface and inner cavity of the machine body, use an oil stone to remove the flash and burrs on the surface of the machine body oil pan, and then wipe it clean with cotton yarn; S113: hoist the oil pan of the engine body onto the fixture with the surface facing the main positioning reference surface of the fixture, and slowly drop it so that the oil pan surface fits the main positioning reference surface of the fixture, and at the same time, the outer cylindrical surfaces of the two process mandrels fall on the vertical positioning blocks at both ends of the fixture respectively; S114: Rotate the stud of the clamping device to slowly move the body until the end face of the flywheel fits into the end face positioning block of the clamp; S115: Use an adjustable wrench to pre-tighten the nuts of the upper clamping plate, and then pre-tighten the nuts of the lower clamping plate; S116: Use a 0.02mm feeler gauge to check the fit between the oil pan surface of the engine body and the main positioning reference surface of the fixture, the process mandrel and the vertical positioning block of the fixture, and the end face of the flywheel of the engine body and the end face positioning block of the fixture. If unqualified, repeat steps S114-S115 until positioning and pre-tightening are completed; S117: Use a torque wrench to tighten the nuts of the upper clamp plate, and then tighten the nuts of the lower clamp plate; S118: Use a 0.02mm feeler gauge again to check the positioning and clamping of the machine body according to the requirements of step S116.

6. The method for machining a circumferential hole in a narrow space of a high-power internal combustion engine body according to claim 1, characterized in that: The specific processing method of the machine body in step S4 includes steps S401-S405; S401: Replace and install a preset non-standard angle accessory head (1) on a CNC machine tool; S402: According to the circumferential hole (3) to be processed, the corresponding tool (2) is installed on the non-standard angle attachment head (1); S403: The CNC machine tool is started, and the tool (2) starts to rotate. According to the planned path preset in the machining program, the non-standard angle attachment head (1) together with the tool (2) moves down into the narrow space of the machine body, and stops moving down after reaching the axis plane of the circumferential hole (3). Then, according to the planned path preset in the machining program, the non-standard angle attachment head (1) rotates until the tool (2) is aligned with the position of the circumferential hole (3) to be machined, and then the non-standard angle attachment head (1) together with the tool (2) moves horizontally toward the position of the circumferential hole (3) until the machining of the circumferential hole (3) is completed; S404: After the processing of the circumferential hole (3) in step S403 is completed, according to the preset planning path of the processing program, the non-standard angle attachment head (1) is first translated to make the tool (2) separate from the circumferential hole (3), and then the non-standard angle attachment head (1) is moved upward to make the tool (2) separate from the narrow space of the machine body, and then the CNC machine tool is stopped and the tool (2) stops rotating; according to the next circumferential hole (3) to be processed, the corresponding tool (2) is replaced; S405: Repeat steps S403-S404 until all the circumferential holes (3) are processed.

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