Boring bar installation structure and processing method for machining bearing holes of vertical compressor crankcase

Abstract

The present invention provides a boring bar installation structure and a processing method for machining bearing holes of a vertical compressor crankcase, and there are relatively high coaxiality requirements between the machined bearing holes. The structure includes a crankcase, a transmission assembly, a boring bar, a bearing seat assembly, and a cutter head assembly. The transmission assembly is used to connect the boring bar and the spindle of the processing device. The boring bar is arranged through the crankcase. The bearing seat assembly is used to install the boring bar. The cutter head assembly is installed on the boring bar. Rough boring bearing holes are respectively opened at both ends and in the middle of the crankcase, and the diameter of the rough boring bearing hole is greater than or equal to the diameter of the boring bar. The bearing seat assembly is located outside the crankcase. The bearing seat assembly includes a bearing seat, a connecting plate, and a positioning pin. The bearing seat is connected to the connecting plate, and the connecting plate is connected to the crankcase through the positioning pin. The connection line of the centers of the bearing seat holes at both ends of the crankcase coincides with the connection line of the centers of the fine boring bearing holes to be machined.

Description

Technical Field

[0001] The present invention relates to the technical field of boring methods, and specifically to a boring bar installation structure and a processing method for machining bearing holes of a vertical compressor crankcase. Background Art

[0002] The crankcase is an important component of a vertical compressor. A crankshaft is installed inside it, and the crankshaft is connected to a piston and a crosshead through a connecting rod. During operation, the crankshaft needs to rotate, which requires it to be connected to the bearing holes on the crankcase through bearings. The bearing holes are generally distributed at both ends and inside the crankcase. When machining the bearing holes, traditionally, boring is used. When boring, especially when machining the holes inside the crankcase, an extended boring bar needs to be inserted into the crankcase, and the tool at the end of the extended boring bar is used to bore the hole. Since the length of the crankcase is relatively long, the extended boring bar is generally more than 1 meter. Therefore, in actual use, the tool at the end of the overly long boring bar will sink due to its weight, resulting in vibration during boring, and the coaxiality between the machined bearing holes is poor and cannot meet the requirements.

[0003] A patent with the publication number CN101823204B discloses a processing method for bearing seat holes of a crankcase. First, the bearing seat hole at one end is finely bored, then the crankcase is rotated 180 degrees and the bearing seat hole at the other end is finely bored. Finally, a boring bar tooling is installed in the finely bored bearing seat hole. The boring bar tooling is positioned by relying on the finely bored bearing seat hole, and then the bearing seat hole inside the crankcase is bored. Since each bearing seat hole is machined separately, the bearing holes at the left and right ends are machined in two steps, and a certain error in coaxiality has occurred between the two holes. The boring bar tooling positions through the bearing holes with a certain coaxiality error at both ends to finely bore the middle bearing hole, which still causes a certain coaxiality error between the middle bearing hole and the bearing holes at both ends. The three bearing holes are not machined in one clamping, and there is a large coaxiality error between the three holes. Summary of the Invention

[0004] Aiming at the problem that there is a certain error in the coaxiality of bearing holes obtained by the traditional method, the present invention provides a boring bar installation structure and a processing method for machining bearing holes of a vertical compressor crankcase, and the bearing holes processed by it have higher coaxiality requirements.

[0005] Its technical solution is as follows: A boring bar installation structure for machining bearing holes of a vertical compressor crankcase, which includes a crankcase, a transmission assembly, a boring bar, a bearing seat assembly, and a cutter head assembly. The transmission assembly is used to connect the boring bar and the spindle of the machining device. The boring bar passes through the crankcase. The bearing seat assembly is used to install the boring bar. The cutter head assembly is installed on the boring bar. It is characterized in that: Coarse boring bearing holes are respectively opened at both ends and in the middle of the crankcase, and the diameter of the coarse boring bearing holes is greater than or equal to the diameter of the boring bar; The bearing seat assembly is located outside the crankcase. The bearing seat assembly includes a bearing seat, a connecting plate, and a positioning pin. The bearing seat is connected to the connecting plate, and the connecting plate is connected to the crankcase through the positioning pin. The connection line of the center of the bearing seat holes at both ends of the crankcase coincides with the connection line of the center of the fine boring bearing holes to be machined.

[0006] It is further characterized in that:

[0007] Positioning holes are respectively opened at both ends of the crankcase, and the positioning holes are used to install the positioning pins. The positioning holes are arranged to avoid the fine boring bearing holes to be machined;

[0008] A protruding portion is provided on the connecting plate in the direction towards the crankcase. The connecting plate contacts the crankcase through the protruding portion;

[0009] The protruding portion is arranged to avoid the fine boring bearing holes to be machined.

[0010] A method for machining bearing holes of a vertical compressor crankcase, which is characterized in that it includes the following steps: Step 1, Coarsely bore the bearing holes at both ends and in the middle of the crankcase. After coarse boring, the diameter of the bearing holes at both ends of the crankcase is greater than or equal to the diameter of the fine boring boring bar;

[0011] Step 2, Install the crankcase on the fine boring workbench, pad it flat, align it, and make the bearing holes at the ends of the crankcase face the spindle of the machining device;

[0012] Step 3, Machine positioning holes at both ends of the crankcase respectively. The positioning holes are used to install the positioning pins of the above-mentioned boring bar installation structure;

[0013] Step 4, Install the bearing seat assemblies of the boring bar installation structure on both ends of the crankcase respectively through the positioning holes. After installation, the connection line of the center of the bearing seat holes of the bearing seat assemblies at both ends coincides with the connection line of the center of the fine boring bearing holes to be machined;

[0014] Step 5, Connect the transmission assembly to the spindle of the machining device, pass the fine boring boring bar through the bearing seat assemblies and the bearing holes at both ends and in the middle of the crankcase and connect it to the transmission assembly;

[0015] Step 6, Install the cutter head assembly on the boring bar and perform tool setting, and machine one of the bearing holes;

[0016] Step 7: Dismantle the cutter head assembly, install it at the position of the next bearing hole to be machined, and perform tool setting. Then machine the next bearing hole.

[0017] Step 8: Repeat Step 7 until all the bearing holes are machined.

[0018] It is further characterized in that:

[0019] The specific steps for installing the crankcase on the fine boring workbench in Step 2 are as follows: a. Pad, align, and clamp at least four supports of the crankcase, then mill the top support surface and machine the connecting bolt holes I on the support surface. After completion, turn it over 180 degrees so that the bottom surface of the support faces upward, and mill the bottom surface of the support to ensure that the heights of all supports are the same. Meanwhile, machine the connecting groove on the bottom surface of the support, and the connecting groove is used to connect with the fine boring workbench.

[0020] b. Place the top surface of the crankcase on the workbench, pad, align, and clamp it. Then the support mounting surface at the bottom of the crankcase faces upward, and finely mill the support mounting surface.

[0021] c. Place the support on the fine boring workbench, then use the support mounting surface at the bottom of the crankcase as the clamping reference surface and fix it on the support surface of the support. Fine-tune the position of the support to align the crankcase, and connect the support and the workbench with a connecting piece and tighten it.

[0022] Before machining the positioning holes in Step 3, first finely mill the left and right end faces of the crankcase.

[0023] The beneficial effects of the present invention are as follows: With such a boring bar installation structure and machining method, the machining alignment scheme of the crankcase is the same as the finished product installation alignment scheme. When machining each bearing hole, it is not necessary to disassemble the boring bar, and the rotation center of the tool is always the same as the rotation center of the boring bar. Each bearing hole is machined under one-time clamping, which can effectively ensure a high coaxiality requirement between each bearing hole. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the present invention;

[0025] Figure 2 It is a schematic installation structure diagram of the bearing seat assembly;

[0026] Figure 3 It is a front view schematic diagram of the support;

[0027] Figure 4 It is a top view schematic diagram of the support;

[0028] Figure 5 It is a front view schematic diagram of the installation of the crankcase and the workbench;

[0029] Figure 6 It is a side view schematic diagram of the installation of the crankcase and the workbench. Detailed implementation mode

[0030] Such as Figure 1 The boring bar installation structure for machining the bearing holes of the vertical compressor crankcase shown, which includes the crankcase 1 after rough milling, the transmission component 2, the boring bar 3, the bearing seat component 4, and the cutter head component 5. The transmission component 2 is used to connect the boring bar 3 and the spindle 6 of the machining device (such as a numerically controlled floor-type milling and boring machine). The boring bar 3 passes through the crankcase 1. The bearing seat component 4 is used to install the boring bar 3. The cutter head component 5 is installed on the boring bar 3. Rough boring bearing holes are respectively opened at both ends and in the middle of the crankcase 1. The diameter of the rough boring bearing hole is greater than or equal to the diameter of the boring bar 3 so that the boring bar 3 can extend in; the bearing seat component 4 is located outside the crankcase 1. Combined Figure 2 with, the bearing seat component 4 includes a bearing seat 41, a connecting plate 42, and a positioning pin 43. The bearing seat 41 is connected to the connecting plate 42. The connecting plate 42 is connected to the crankcase 1 through the positioning pin 43. The boring bar 3 can be installed on the sliding bearing on the bearing seat 41. The connection line of the center of the bearing seat holes at both ends of the crankcase 1 coincides with the connection line of the center of the fine boring bearing holes to be machined, so that the rotation center of the boring bar is on the preset connection line of the center of the fine boring bearing holes, ensuring a high coaxiality requirement between each bearing hole. Specifically, positioning holes are respectively opened at both ends of the crankcase 1. The positioning holes are used to install the positioning pin 43, and the positioning holes are arranged to avoid the fine boring bearing holes to be machined.

[0031] Compared with the existing boring bar tooling, this scheme is installed on the crankcase 1 after rough machining and can be used without fine boring the bearing holes at both ends. The bearing holes at both ends only need rough boring; while the bearing seat component 4 is installed outside the crankcase 1 through the connecting plate 42 and the positioning pin 43, and is positioned through the positioning pin 43, without relying on the finely milled bearing holes at both ends for positioning, ensuring the coaxiality.

[0032] In addition, a protruding portion 44 is provided on the connecting plate 42 in the direction towards the crankcase 1. The connecting plate 42 contacts the crankcase 1 through the protruding portion 44, so that a certain gap is formed between the connecting plate 42 and the crankcase 1. At the same time, the protruding portion 44 is arranged to avoid the fine boring bearing holes to be machined. With such a setting, the cutting tool can extend into the gap during boring, so as to be able to drill through the entire bearing hole, which is convenient for use.

[0033] The method for machining the bearing holes of the vertical compressor crankcase, combined Figure 1 with, includes the following steps: Step 1, rough bore the bearing holes at both ends and in the middle of the crankcase. After rough boring, the diameter of the bearing holes at both ends of the crankcase is greater than or equal to the diameter of the fine boring bar.

[0034] Step 2, install the crankcase on the fine boring workbench, pad it flat, align it, and make the bearing holes at the end of the crankcase face the spindle 6 of the machining device; its specific installation steps are: a. Combined Figure 3 、Figure 4 Level, align, and clamp at least four supports 7 of the crankcase, then mill the top support surface 71 with a roughness of Ra3.2 for all of them, and drill the connecting bolt holes 72 on the support surface 71. After completion, turn it over by 180 degrees so that the bottom surface 73 of the support 7 faces upward and process the bottom surface 73 of the support 7 with a roughness of Ra3.2 for all of them to ensure that the heights of all supports 7 are the same. At the same time, process the connecting groove 74 on the bottom surface of the support 7, and the connecting groove 74 is used to connect with the fine boring workbench 8.

[0035] b. Place the top surface of the crankcase 1 on the workbench 8, level, align, and clamp it. Then, with the support mounting surface at the bottom of the crankcase 1 facing upward, finely mill the support mounting surface with a roughness of Ra3.2 and a flatness of 0.025.

[0036] c. Place the support on the fine boring workbench, and then use the support mounting surface at the bottom of the crankcase as the clamping reference surface and fix it on the support surface of the support. Fine-tune the position of the support to align the crankcase, and connect and tighten the support and the workbench with fastening bolts and nuts. After the installation is completed, as shown in Figure 5 、 Figure 6 shown.

[0037] Step 3: Finely mill the left and right end faces of the crankcase 1, and process positioning holes at both ends of the crankcase according to the dimensions of the fine boring bearing holes to be processed and the dimensions of the connecting plate 42 respectively. The positioning holes are used to install the positioning pins 43 of the above boring bar mounting structure.

[0038] Step 4: Install the bearing seat assemblies 4 of the boring bar mounting structure at both ends of the crankcase through the positioning holes. After the installation is completed, the connection line of the centers of the bearing seat holes of the bearing seat assemblies at both ends coincides with the connection line of the centers of the fine boring bearing holes to be processed.

[0039] Step 5: Connect the transmission component to the main shaft of the processing device, and pass the fine boring bar through the bearing seat assemblies at both ends and the bearing holes at both ends and in the middle of the crankcase and connect it to the transmission component.

[0040] Step 6: Install the cutter head assembly at position A of the boring bar and perform tool setting. Then, semi-precisely bore and precisely bore the middle bearing hole with a roughness of Ra3.2.

[0041] Step 7: Disassemble the cutter head assembly and install it at position C of the boring bar and perform tool setting. Then, semi-precisely bore and precisely bore the end bearing hole with a roughness of Ra3.2. The coaxiality of the left end bearing hole relative to the middle bearing hole is φ0.025mm.

[0042] Step 8: Dismantle the cutter head assembly, install it at boring bar B and perform tool setting. Carry out reverse semi-finishing and finishing boring on the bearing holes at the other end, with a roughness of Ra3.2. The coaxiality of the right-end bearing hole relative to the middle and left-end bearing holes is φ0.025 mm. The three bearing holes are machined under one clamping, ensuring high coaxiality requirements between the bearing holes and also ensuring the perpendicularity requirements of the bearing holes relative to the two end faces.

[0043] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those familiar with the technology within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for machining a bearing hole of a vertical compressor crankcase, characterized in that: The boring bar mounting structure for machining the bearing holes of the vertical compressor crankcase includes a crankcase, a transmission assembly, a boring bar, a bearing seat assembly, and a cutter head assembly. The transmission assembly is used to connect the boring bar and the spindle of the machining device. The boring bar passes through the crankcase. The bearing seat assembly is used to mount the boring bar. The cutter head assembly is mounted on the boring bar. The two ends and the middle of the crankcase are respectively provided with rough boring bearing holes, and the diameter of the rough boring bearing holes is greater than or equal to the diameter of the boring bar. The bearing seat assembly is located outside the crankcase. The bearing seat assembly includes a bearing seat, a connecting plate, and a positioning pin. The bearing seat is connected to the connecting plate, and the connecting plate is connected to the crankcase through the positioning pin. The connection line of the centers of the bearing seat holes at both ends of the crankcase coincides with the connection line of the centers of the fine boring bearing holes to be machined. Positioning holes are respectively provided at both ends of the crankcase. The positioning holes are used to mount the positioning pins, and the positioning holes are arranged to avoid the fine boring bearing holes to be machined. A protruding portion is provided on the connecting plate facing the direction of the crankcase. The connecting plate contacts the crankcase through the protruding portion. The protruding portion is arranged to avoid the fine boring bearing holes to be machined. The machining method includes the following steps: Step 1, rough bore the bearing holes at both ends and in the middle of the crankcase. After rough boring, the diameter of the bearing holes at both ends of the crankcase is greater than or equal to the diameter of the fine boring boring bar. Step 2, machine positioning holes at both ends of the crankcase respectively. The positioning holes are used to mount the positioning pins of the boring bar mounting structure. Step 3, mount the crankcase on the fine boring workbench, pad it flat, align it, and make the bearing holes at the ends of the crankcase face the spindle of the machining device. Step 4, respectively mount the bearing seat assemblies of the boring bar mounting structure on both ends of the crankcase through the positioning holes. After installation, the connection line of the centers of the bearing seat holes of the bearing seat assemblies at both ends coincides with the connection line of the centers of the fine boring bearing holes to be machined. Step 5, connect the transmission assembly to the spindle of the machining device, pass the fine boring boring bar through the bearing seat assemblies and the bearing holes at both ends and in the middle of the crankcase and connect it to the transmission assembly. Step 6, mount the cutter head assembly on the boring bar and perform tool setting, and perform fine boring machining on one of the bearing holes. Step 7, disassemble the cutter head assembly and install it at the position of the next bearing hole to be machined and perform tool setting, and perform fine boring machining on the next bearing hole. Step 8, repeat Step 7 until all the bearing holes are machined. The specific steps for mounting the crankcase on the fine boring workbench in Step 2 are as follows: a. Pad, align, and clamp at least four supports of the crankcase, then mill the top support surface and machine the connecting bolt holes I on the support surface. After completion, turn it over 180 degrees so that the bottom surface of the support faces up and mill the bottom surface of the support to ensure that the heights of all supports are the same. At the same time, machine the connecting groove on the bottom surface of the support, and the connecting groove is used to connect with the fine boring workbench. b. Place the top surface of the crankcase on the workbench, pad it flat, align it, and clamp it. Then the support mounting surface at the bottom of the crankcase faces up and finely mill the support mounting surface. c. Place the support on the fine boring workbench, then use the support mounting surface at the bottom of the crankcase as the clamping reference surface and fix it on the support surface of the support. Fine-tune the position of the support to correct the crankcase, and connect the support to the workbench with a connecting piece and tighten it.

2. The machining method of the bearing hole of the vertical compressor crankcase according to claim 1, characterized in that: Before machining the positioning holes in Step 3, first finish-mill the left and right end faces of the crankcase.

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