The clamping method of machining the rocker arm swash plate on the turning and milling compound machine tool

Abstract

The invention discloses a clamping method for processing a rocker arm swash plate on a dual-spindle chuck turning and milling compound machine tool, comprising the following steps: the first step is to manufacture a mold-type soft jaw according to the shape structure of the rocker arm swash plate; the second step is to install two mold-type soft jaws on a two-jaw chuck, and use the two-jaw chuck to drive the mold-type soft jaws to clamp the rocker arm swash plate blank; the third step is to process a limiting threaded hole on the side of the mold-type soft jaw, and use a limiting screw to realize the positioning of the rocker arm swash plate blank in the direction of the ear shaft hole; the fourth step is to process the corresponding position of the rocker arm swash plate blank to obtain a semi-finished rocker arm swash plate machined part; the fifth step is to manufacture a post-processing fixture according to the structure of the semi-finished rocker arm swash plate machined part; the sixth step is to use the post-processing fixture to position and clamp the semi-finished rocker arm swash plate machined part, and then process the semi-finished rocker arm swash plate machined part to obtain a finished rocker arm swash plate. The invention has the characteristics of being able to effectively improve the rigidity of the product and stabilize the processing quality.

Description

Technical Field

[0001] The invention relates to a processing and clamping method for a rocker arm swash plate, in particular to a processing and clamping method for a rocker arm swash plate on a turning and milling compound machine tool. Background Art

[0002] The rocker arm swash plate is a key force-bearing part in the hydraulic pump. It is often a special-shaped forging part with a large number of spatial intersections and high processing precision requirements. The processing surface almost covers the entire product. In actual processing, the process steps are very long, and there are many fixtures involved, and the product processing cycle is also long. In order to make full use of new equipment, new processes, and new methods, improve product processing efficiency, improve product processing quality, and shorten product production cycles, a relatively efficient turning and milling compound machine tool is used for processing. The product is processed in two steps from the forging blank, that is, all the shapes and spatial dimensions of the entire product are processed on a turning and milling compound equipment with double chucks, and the processing of bearing holes, threaded holes and other features is realized. Due to the particularity of the product shape, solving the clamping problem of such products on efficient equipment has become the key to whether new equipment, new processes, and new methods can be applied.

[0003] At present, the usual method of processing rocker arm swash plates on high-efficiency equipment is to make process bosses on the blank, such as Figure 1 As shown. First, clamp the process boss to complete the processing of the belly surface and the bearing hole, and then use the fixture to remove the process boss to complete the processing of the back of the product. However, the size and length of the process boss will affect the deformation of the product after processing. For example, if the process boss is large, when it is cut off at the end, it will affect the distribution of product strength and stress, which may cause the processing shape of the first step to deform and destroy the size of the spatial intersection; if the process boss is too small and the strength and rigidity are insufficient, it will affect the processing effect and quality during the first step of processing, such as vibration of the knife and instability of the spatial intersection, etc.; secondly, since most of the blanks are forgings, the forged process bosses generally have a certain draft angle or a parting line, which makes the shape and size of the process boss inconsistent. When the first step is clamped, the draft angle or the parting line will exist, and the reliability and stability of the blank process boss as a positioning reference clamping will cause the final wall thickness of the product to be inconsistent, affecting the performance of the entire product. Therefore, the existing technology has the problems of poor rigidity and unstable processing quality. Summary of the invention

[0004] The purpose of the present invention is to provide a clamping method for processing a rocker arm swash plate on a turning and milling compound machine tool. The present invention has the characteristics of being able to effectively improve product rigidity and stabilize processing quality.

[0005] The technical solution of the present invention is a clamping method for machining a rocker arm swash plate on a turning and milling compound machine tool, comprising the following steps:

[0006] The first step is to make mold-type soft claws that match the non-machined surfaces of the two bearing holes of the rocker arm swash plate according to the shape structure of the rocker arm swash plate;

[0007] The second step is to install two mold-type soft jaws on the two jaw seats of the two-jaw chuck respectively, and use the hydraulic system of the machine tool to drive the two mold-type soft jaws to clamp the rocker arm swash plate blank;

[0008] The third step is to process a limiting threaded hole on the side of each mold-type soft claw, and use the limiting screw to realize the positioning of the rocker arm swash plate blank in the axial direction of the two trunnion holes;

[0009] Step 4: After the rocker arm swash plate blank is completely positioned, the belly surface, threaded holes, pin holes on the belly surface and corresponding internal shapes of the rocker arm swash plate are processed, and the rocker wall, two bearing shafts and end faces of the rocker arm swash plate are rough-processed to obtain the semi-finished rocker arm swash plate;

[0010] Step 5: Make a post-processing fixture according to the structure of the semi-finished rocker arm swash plate;

[0011] Step 6. Use the post-processing fixture to position and clamp the semi-finished rocker arm swash plate, and then process the semi-finished rocker arm swash plate to complete the finishing of the back of the rocker arm swash plate, the ear shaft hole and its end face, the rocker arm, the center height and eccentricity of the ear shaft hole, and the size of the spatial intersection to obtain the finished rocker arm swash plate.

[0012] In the clamping method for machining the rocker arm swash plate on a turning and milling machine tool, the mold-type soft jaw includes a soft jaw body, and two working surfaces inside the soft jaw body are provided with contour grooves corresponding to the rocker arm swash plate.

[0013] In the clamping method for processing the aforementioned rocker arm swash plate on a turning and milling compound machine tool, the post-processing fixture includes a fixture base, three straight grooves are provided at the bottom of the fixture base, each straight groove is provided with a mounting screw hole, which is locked by mounting screws and locking nuts. A hollow cylinder is provided at the upper end of the fixture base, a positioning mandrel is provided in the hollow cylinder, and a tensioning screw is provided in the positioning mandrel; a product directional pin is also provided at the upper end surface of the hollow cylinder.

[0014] In the clamping method for machining the aforementioned rocker arm swash plate on a turning and milling compound machine tool, a threaded surface is provided on the positioning mandrel, and a machining avoidance groove is provided on the upper end surface of the positioning mandrel.

[0015] In the clamping method for machining the aforementioned rocker arm swash plate on a turning and milling compound machine tool, a directional pin cooperating with the positioning mandrel is provided inside the hollow cylinder, and a directional groove corresponding to the directional pin is provided on the outer cylindrical surface of the positioning mandrel.

[0016] In the clamping method of the aforementioned rocker arm swash plate on a turning and milling machine tool, the clamping process of the post-processing fixture is as follows:

[0017] 1) The three straight grooves on the bottom of the fixture chassis are connected to the three-jaw chuck through mounting screws and locking nuts to achieve quick-change connection;

[0018] 2) Loosen the tension screw and pull the positioning mandrel out a certain distance;

[0019] 3) Screw the threaded hole on the belly surface of the semi-finished rocker arm swash plate workpiece onto the threaded surface of the positioning mandrel, and push the semi-finished rocker arm swash plate workpiece to move the positioning mandrel, so that the positioning pin on the small end surface of the fixture base is inserted into the positioning hole of the semi-finished rocker arm swash plate workpiece to achieve positioning and orientation;

[0020] 4) Tighten the tightening screw so that the semi-finished rocker arm swash plate workpiece is subjected to the pulling force of the positioning mandrel to achieve compression and complete the complete positioning and clamping of the product.

[0021] Compared with the prior art, the present invention utilizes the forming principle of the punch and die in the mold to produce mold-type soft jaws, so as to realize the rapid clamping and positioning of the rocker arm swash plate blank, and ensure that the rocker arm swash plate blank has a precise position and sufficient rigidity during processing; the two mold-type soft jaws can cooperate with each other to adapt to the slight differences in the blank's appearance, and avoid the occurrence of poor fitting due to high hardness, small wear. At the same time, the present invention uses a specific post-processing fixture and a directional movable positioning mandrel positioning and clamping method to achieve the clamping and positioning of the product. Through the mutual cooperation between the mold-type soft jaws and the post-processing fixture, there is no need to set a process boss during the entire processing process of the rocker arm swash plate, and the non-processed surface at the two bearing holes in the blank can be directly used as the clamping reference to ensure that the product's spatial dimensions are processed under the final shape of the product, and solve the deformation caused by the clamping force and the stress change after removing the large margin. After clamping, the product has sufficient rigidity and reliable positioning and clamping. Moreover, the rocker arm swash plate processed by this method has a uniform, stable and consistent wall thickness of the bearing hole; during the processing of the spatial intersection size, a small amount of material is removed, there is no large stress change, and the size is relatively stable; it can also shorten the entire processing cycle of such products, save investment in production resources such as machine tools and fixtures, and reduce production costs.

[0022] The present invention solves the clamping problem of rocker wall inclined plate parts on the dual-spindle turning and milling compound high-efficiency machining machine tool by manufacturing the mold-type soft jaws of the two-jaw chuck and the quick-change tooling on the three-jaw chuck, thereby realizing the high-efficiency machining of products on the turning and milling compound machine tool with new equipment, new technology and new process, greatly improving the product machining efficiency, improving the product machining quality, shortening the entire product machining cycle, and finding a breakthrough for the machining direction of similar parts.

[0023] In summary, the present invention has the characteristics of being able to effectively improve product rigidity and stabilize processing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is the structural view of the traditional rocker arm swash plate during machining (including the process boss);

[0025] Figure 2 It is a structural schematic diagram of the mold-type soft claw of the present invention;

[0026] Figure 3 This is a state diagram of the mold-type soft jaws and the rocker arm swash plate blank being clamped;

[0027] Figure 4 It is the structural view of the post-processing fixture;

[0028] Figure 5 is an internal view of the post-processing fixture;

[0029] Figure 6 It is a structural view between the positioning mandrel and the hollow cylinder;

[0030] Figure 7 It is the clamping view between the post-processing fixture and the rough-machined part of the rocker arm swash plate.

[0031] The markings in the attached drawings are: 1-soft claw body, 2-outline groove, 3-clamp base, 4-straight groove, 5-locking nut, 6-mounting screw, 7-hollow cylinder, 8-positioning mandrel, 9-tensioning screw, 10-product orientation pin, 11-processing avoidance groove, 12-orientation pin, 13-orientation groove. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0033] Embodiment. A clamping method for machining a rocker arm swash plate on a turning and milling machine tool,

[0034] The following steps are involved:

[0035] First step

[0036] 1. According to the appearance and structure of the rocker arm swash plate product, make mold-type soft claws that match the non-machined surfaces of the two bearing holes of the rocker arm swash plate ( Figure 1 ). (The product is considered as the male die, and the soft claws are considered as the female die)

[0037] 2. The headstock chuck uses a four-jaw or two-jaw chuck. When the chuck is clamped, the rocker arm inclined plate blank is synchronously approached by two mold-type soft jaws to achieve accurate positioning and clamping of the product ( Figure 2-3 ).

[0038] 3. A threaded hole is machined on the side of the soft jaw of the rocker arm swash plate to adjust the position of the two bearing end faces of the product, realize the positioning of the rocker arm swash plate blank in the axial direction of the ear shaft hole, ensure the uniformity of the blank allowance, and eliminate the influence of the large cutting force generated when rough drilling the two bearing holes on the clamping state.

[0039] like Figure 2 and 3 As shown in the figure, before clamping the two rocker arm swash plate soft claws, first place the rocker arm swash plate blank against the rocker arm swash plate soft claws, and make the rocker arm swash plate blank fit with the limit screw. After clamping, tighten the locking nut on the other soft claw to eliminate the movement of the product in the direction of the bearing hole due to the cutting force when drilling the two bearing holes. The bearing hole and its end face and rocker arm have a certain processing allowance. After completing all the processing behind the product in the second step, fine processing is performed to avoid deformation of the product due to changes in thickness or strength.

[0040] The mold-type soft claw comprises a soft claw body 1, and two end surfaces inside the soft claw body 1 are provided with arc-shaped grooves 2 corresponding to the rocker arm swash plate.

[0041] Second step

[0042] 1. Combined with the state of the rocker arm swash plate rough-machined parts after the first step, using the relationship between the belly surface, pin hole, locating hole, and threaded hole, a fixture (i.e., post-processing fixture) is made for thread tightening, belly surface and locating hole positioning, and pin hole orientation, to complete the processing of the product back, trunnion hole and end face, rocker arm, trunnion hole center height and eccentricity and other related dimensions, and spatial intersection dimensions. Post-processing fixtures such as Figure 4-7 shown.

[0043] The post-processing fixture includes a fixture base 3, and three straight grooves 4 are provided at the bottom of the fixture base 3 (used to cooperate with the three jaws of the hydraulic three-jaw chuck for positioning). Each straight groove 4 is provided with a mounting screw hole, which is locked by the mounting screw 6 and the locking nut 5. A hollow cylinder 7 is provided at the upper end of the fixture base 3, and a positioning core shaft 8 is provided in the hollow cylinder 7, and a tensioning screw 9 is provided in the positioning core shaft 8; a product orientation pin 10 is also provided at the upper end surface of the hollow cylinder 7.

[0044] The positioning mandrel 8 is provided with a threaded surface, and the upper end surface of the positioning mandrel 8 is provided with a machined avoidance groove 11 .

[0045] The hollow cylinder 7 is provided with an orientation pin 12 matched with the positioning core shaft 8 , and the outer cylindrical surface of the positioning core shaft 8 is provided with an orientation groove 13 corresponding to the orientation pin 12 .

[0046] There are three straight grooves on the chassis mounting surface of the post-processing fixture, which are used to achieve quick-change connection with the three-jaw chuck; there is an directional groove on the positioning mandrel, which is oriented through the pin hole embedded in the cylindrical hole on the fixture base, so that the positioning mandrel can only move axially to achieve tightening action; the diameter of the positioning mandrel is consistent with the diameter of the positioning hole on the belly surface of the semi-finished machined part of the rocker arm swash plate, and is used with the directional pin to position the product; there is also a threaded surface on the positioning mandrel to tighten the product; the four grooves above are convenient for cutting when processing the four grooves on the back of the product after the product is positioned and tightened.

[0047] Specific clamping method of post-processing fixture:

[0048] Loosen the tightening screw (can be tightened and loosened manually or automatically), and pull the positioning mandrel out a certain distance;

[0049] Screw the threaded hole on the belly surface of the rough-machined rocker arm swash plate product onto the threaded surface on the positioning mandrel, and push the product to move the positioning mandrel so that the locating pin on the hollow cylinder is inserted into the locating hole on the belly surface of the rough-machined rocker arm swash plate product to achieve positioning and orientation.

[0050] Start the hydraulic pressure or tighten the threaded tie rod to make the product receive the pulling force of the mandrel and achieve product compaction. Figure 7 shown.

Claims

1. The clamping method of the rocker arm swash plate on a turning and milling compound machine tool is characterized by: The following steps are involved: The first step is to make mold-type soft claws that match the non-machined surfaces of the two bearing holes of the rocker arm swash plate according to the shape structure of the rocker arm swash plate; The second step is to install two mold-type soft jaws on the two jaw seats of the two-jaw chuck respectively, and use the hydraulic system of the machine tool to drive the two mold-type soft jaws to clamp the rocker arm swash plate blank; The third step is to process a limiting threaded hole on the side of each mold-type soft claw, and use the limiting screw to realize the positioning of the rocker arm swash plate blank in the axial direction of the two trunnion holes; Step 4: After the rocker arm swash plate blank is completely positioned, the belly surface, threaded holes, pin holes on the belly surface and corresponding internal shapes of the rocker arm swash plate are processed, and the rocker wall, two bearing shafts and end faces of the rocker arm swash plate are rough-processed to obtain the semi-finished rocker arm swash plate; Step 5: Make a post-processing fixture according to the structure of the semi-finished rocker arm swash plate; Step 6. Use the post-processing fixture to position and clamp the semi-finished rocker arm swash plate, and then process the semi-finished rocker arm swash plate to complete the finishing of the back of the rocker arm swash plate, the ear shaft hole and its end face, the rocker arm, the center height and eccentricity of the ear shaft hole, and the size of the spatial intersection to obtain the finished rocker arm swash plate.

2. The clamping method for machining a rocker arm swash plate on a turning and milling compound machine tool according to claim 1 is characterized in that: The mold-type soft claw comprises a soft claw body (1), and two working surfaces inside the soft claw body (1) are provided with outer shape grooves (2) corresponding to the rocker arm swash plate.

3. The clamping method for machining a rocker arm swash plate on a turning and milling compound machine tool according to claim 1 is characterized in that: The post-processing fixture comprises a fixture base (3), three straight grooves (4) are provided at the bottom of the fixture base (3), each straight groove (4) is provided with a mounting screw hole, which is locked by a mounting screw (6) and a locking nut (5), a hollow cylinder (7) is provided at the upper end of the fixture base (3), a positioning mandrel (8) is provided in the hollow cylinder (7), and a tensioning screw (9) is provided in the positioning mandrel (8); a product orientation pin (10) is also provided at the upper end surface of the hollow cylinder (7).

4. The clamping method for machining a rocker arm swash plate on a turning and milling machine tool according to claim 3 is characterized in that: A threaded surface is provided on the positioning mandrel (8), and a machined avoidance groove (11) is provided on the upper end surface of the positioning mandrel (8).

5. The clamping method for machining a rocker arm swash plate on a turning and milling compound machine tool according to claim 4 is characterized in that: A directional pin (12) matching with the positioning core shaft (8) is arranged inside the hollow cylinder (7), and a directional groove (13) corresponding to the directional pin (12) is arranged on the outer cylindrical surface of the positioning core shaft (8).

6. The clamping method for machining a rocker arm swash plate on a turning and milling compound machine tool according to claim 5 is characterized in that: The clamping process of the post-processing fixture is: 1) The three straight grooves on the bottom of the fixture base are connected to the three-jaw chuck through mounting screws and locking nuts to achieve quick-change connection; 2) Loosen the tension screw and pull the positioning mandrel out a certain distance; 3) Screw the threaded hole on the belly surface of the semi-finished rocker arm swash plate machined part onto the threaded surface of the positioning mandrel, and push the semi-finished rocker arm swash plate machined part to move the positioning mandrel, so that the product orientation pin on the upper end surface of the hollow cylinder is inserted into the positioning hole of the semi-finished rocker arm swash plate machined part to achieve positioning and orientation; 4) Tighten the tightening screw so that the semi-finished rocker arm swash plate workpiece is subjected to the pulling force of the positioning mandrel to achieve compression and complete the complete positioning and clamping of the product.

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