Machining method and clamp for reducing deformation of oil chamber cover plate

Abstract

The invention relates to the technical field of machining, in particular to a machining method and clamp for reducing deformation of an oil chamber cover plate, after casting of the oil chamber cover plate is completed, destressing treatment is conducted, part of allowance is roughly machined, and natural aging or artificial aging is conducted; semi-finishing the end face, the outer circle and the inner hole of the oil chamber cover plate, eliminating the deformed part, and marking the position relationship among the holes; according to the method, most of holes of the oil chamber cover plate are machined based on drawing requirements, a clamp is used for clamping and finish machining of the end face of the oil chamber cover plate based on the positions of the holes, and finally, the remaining unmachined holes are finish machined, according to the method, part internal stress can be released in advance by removing stress and reducing part size or form and location tolerance out-of-tolerance caused by stress deformation, and most allowance is removed through rough machining; the special clamp is used for clamping, part deformation caused by three-jaw clamping is avoided, deformation of the part in the machining process is reduced, and meanwhile the perpendicularity and parallelism of the end face of the part and the form and location tolerance requirements of jumping of an inner hole and the like are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical processing, in particular to a machining method and clamp for reducing deformation of an oil chamber cover plate. BACKGROUND

[0002] The oil chamber cover plate is one of the parts of a supercharger, and is a casting, the material of which is gray cast iron GG20 (corresponding to gray iron 200 in the domestic standard GB9439). The end face of the oil chamber cover plate has a high form and position tolerance requirement. When machining is performed by using only a common general clamp (such as a three-jaw clamp), deformation will inevitably occur due to the influence of the clamping force of the machine tool and the particularity of the structure of the part, so that the perpendicularity, parallelism of the end face and the runout requirement of the inner hole cannot be guaranteed.

[0003] In order to guarantee the form and position tolerance requirements of the end face and the inner hole of the oil chamber cover plate, a machining method and clamp for reducing deformation of the oil chamber cover plate are urgently needed to clamp and machine the oil chamber cover plate. SUMMARY

[0004] The present application aims to provide a machining method and clamp for reducing deformation of an oil chamber cover plate, and aims to solve the problem that the oil chamber cover plate will deform when a common general clamp is used to clamp and machine the oil chamber cover plate.

[0005] To achieve the above-mentioned purpose, the present application provides a machining method for reducing deformation of an oil chamber cover plate, comprising the following steps: After the oil chamber cover plate is cast, stress relief treatment is performed, the remaining amount of the rough machining part is removed, and natural aging or artificial aging is performed; The end face, outer circle and inner hole of the semi-finished oil chamber cover plate are machined, the deformed part is eliminated, and the position relationship between the holes is marked; Most of the holes of the oil chamber cover plate are machined based on the drawing requirements, the clamp is clamped based on the position of the holes, the end face of the oil chamber cover plate is finished, and finally, the remaining holes that have not been machined are finished.

[0006] The stress treatment method includes heat treatment, vibration aging and natural aging.

[0007] The natural aging is placed for more than 20 days, the artificial aging temperature is controlled at 500-550℃, the holding time is 2 hours, the cooling speed is ≤30℃ / h until the temperature is below 200℃, and then the furnace is discharged and air-cooled to room temperature.

[0008] In the second aspect, the present application also provides a machining clamp for reducing deformation of an oil chamber cover plate, which is applied to the machining method for reducing deformation of an oil chamber cover plate as described in the first aspect, and is characterized in that, The first clamp comprises a first equal-height block, a second equal-height block, a pressing plate, a hexagonal nut, a bolt and a machine tool workbench, the first equal-height block is arranged on the top of the machine tool workbench, the second equal-height block is arranged on the top of the machine tool workbench, the pressing plate is assembled on the end of the second equal-height block away from the machine tool workbench, the hexagonal nut is arranged on the side of the pressing plate away from the second equal-height block, and the bolt is connected with the hexagonal nut and penetrates through the machine tool workbench; The second clamp comprises a cushion block, a first inner hexagonal cylindrical head screw, a cylindrical pin, a base, a stop lever, a second inner hexagonal cylindrical head screw, a positioning shaft, an elastic sleeve, a countersunk screw and a third inner hexagonal cylindrical head screw, the stop lever is arranged on one side of the base, the second inner hexagonal cylindrical head screw is threadedly connected with the base and penetrates through the stop lever, the cushion block is assembled on the side of the base away from the stop lever, the first inner hexagonal cylindrical head screw is threadedly connected with the base and penetrates through the cushion block, the positioning shaft is arranged on the side of the cushion block away from the base, the elastic sleeve is arranged in the positioning shaft, the countersunk screw is assembled on one side of the positioning shaft, and the third inner hexagonal cylindrical head screw is threadedly connected with the cushion block and penetrates through the positioning shaft.

[0009] The elastic sleeve is made of 65Mn spring steel, and six openings are arranged on the cylindrical surface.

[0010] The oil chamber cover plate is subjected to stress relief treatment after casting, and the remaining amount of rough machining part is subjected to natural aging or artificial aging; the oil chamber cover plate end face, outer circle and inner hole are subjected to semi-finishing, the deformation part is eliminated, and the position relationship between holes is marked; most of the holes of the oil chamber cover plate are machined based on the drawing requirements, and the remaining holes are machined based on the hole position using a clamp; the end face of the oil chamber cover plate is finished, and finally, the remaining holes are finished.

[0011] The comparison table of various parameters before and after using the method is as follows:

[0012] In order to make the technical solutions and advantages of the present application clearer, the embodiments of the present application are further described in detail below.

[0013] The terms "first", "second", "third", and "fourth" and the like in the description and in the claims of the present application and in the recitations of the drawings are used for distinguishing between similar objects and are not necessarily used in a sequential or chronological sense. Also, the terms "comprise", "comprising", "including", and "having" and variations thereof in the present description and in the claims of the present application are intended to cover both the case where the specified features are included and the case where the specified features are not included. For example, a process, method, system, product, or apparatus that comprises a list of steps or units is not limited to the listed steps or units but can also include other steps or units not listed, or can also include other steps or units inherent to the process, method, system, product, or apparatus.

[0014] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.), and signals involved in the present application are all authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data need to comply with relevant laws, regulations, and standards of relevant countries and regions. For example, the strain data, acceleration data, displacement data, pressure data, video data, etc. involved in the present application are obtained under full authorization.

[0015] Figure 1 is a flow chart of the processing method for reducing deformation of the oil chamber cover plate provided by the present application.

[0016] Figure 2 is a first clamping structure schematic diagram of the oil chamber cover plate processing each hole of the processing clamp for reducing deformation of the oil chamber cover plate provided by the present application.

[0017] Figure 3 is a second clamping schematic diagram of the processing clamp for reducing deformation of the oil chamber cover plate provided by the present application.

[0018] Figure 4 is a second clamping top view of the processing clamp for reducing deformation of the oil chamber cover plate provided by the present application.

[0019] Figure 5 is Figure 4 sectional view along A-A plane.

[0020] Figure 6 is Figure 4 sectional view along B-B plane.

[0021] Figure 7 is Figure 6 enlarged view at detail C.

[0022] In the figure: 1 - oil chamber cover plate, 2 - cushion block, 3 - inner hexagonal cylindrical head screw, 4 - cylindrical pin, 5 - base, 6 - stop lever, 7 - inner hexagonal cylindrical head screw, 8 - positioning shaft, 9 - elastic sleeve, 10 - countersunk screw, 11 - inner hexagonal cylindrical head screw, 20 - first equal height block, 21 - second equal height block, 22 - pressing plate, 23 - hexagonal nut, 24 - bolt, 25 - machine tool workbench. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, the embodiments described below by referring to the accompanying drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0024] Referring to Figures 1 to 7 The present application provides a processing method for reducing deformation of an oil chamber cover plate, comprising the following steps: S1 After the oil chamber cover plate is cast, stress relief treatment is performed, the excess amount of rough machining part is removed, and natural aging or artificial aging is performed, In the embodiments of the present application, the part should be subjected to stress relief treatment after casting to reduce the internal stress of the part and reduce the stress deformation to cause the size or shape tolerance of the part to be out of tolerance. The stress relief method can use stress relief annealing (the casting is heated to 500-600℃, and slowly cooled after holding for 2-8 hours, which can effectively eliminate the internal stress), high temperature annealing (heated to 850-900℃, holding for 2-5 hours, and then slowly cooled to 400-500℃ to be discharged and air cooled), vibration aging method (vibration is applied to the casting to vibrate at the natural frequency for several minutes to several tens of minutes, which can eliminate and homogenize the residual stress), natural aging method (the casting is placed outdoors for a long time, and the residual stress is naturally weakened after several months to several years), etc.

[0025] When the part starts to be machined, an appropriate excess amount (the single-sided excess amount of the part is controlled to be between 1-5-2-5mm) should be left. The three-jaw or four-jaw is used to clamp the outer circle of the part blank, the part is aligned according to the starting size reference and the outer circle of the blank, an appropriate excess amount is left, and the end face, outer circle, inner hole, etc. are turned. The parameters are shown in the following table: Machining equipment Tool type Rotational speed (unit: r / s) Feed rate (unit: mm / r) Climb (unit: mm) C630 Tool holder (K30 insert of R or S type) 180-270 0-15-0-3 0-5-3 After rough machining, natural aging should be carried out, and the part is placed for more than 20 days (the natural aging time of gray cast iron GG20 after casting is usually 6-12 months, and from the completion of casting to the completion of rough machining, a period has been experienced. The 20-day natural aging here is an empirical value, which is derived from the fact that in a certain processing, the part deforms greatly after rough machining, and the part is forced to be placed for about a month, and when the part is processed again, the deformation amount of the part is obviously reduced, and in combination with the jig processing in the application, the qualified product processing can be ensured), and when subsequent processing is carried out and there is no enough time for natural aging due to urgent production cycle of the part, low-temperature artificial aging can be carried out (it is recommended that the temperature is controlled at 500-550 DEG C, the holding time is 2 hours, the furnace cooling is carried out until the temperature is below 200 DEG C, the cooling speed is less than or equal to 30 DEG C / h, and then the part is taken out of the furnace and air-cooled to room temperature).

[0026] S2 semi-finishing oil chamber cover plate end face, outer circle and inner hole, eliminating the deformed part, and scribing the positional relationship between the holes, In the embodiment of the application, three claws or four claws are used to clamp the outer circle of the part blank, the part is aligned according to the outer circle and the end face processed during rough machining, an appropriate allowance is left, the end face, the outer circle, the inner hole and the like are turned, the deformed part of the part after secondary aging treatment is removed, the part is re-regularized, and the error during subsequent scribing processing of the holes is reduced. The parameters are shown in the following table: Machining equipment Tool type Rotational speed (unit: r / s) Feed rate (unit: mm / r) Climb (unit: mm) C630 Tool holder (K30 insert of R or S type) 180-270 0-1-0-2 0-5-1 According to the positional relationship between the holes of the part, the outer circle of the part after semi-finishing is aligned, the center line is scribed on the end face of the hole to be processed, and is led to the outer circle of the blank, which is used for alignment during subsequent processing.

[0027] S3 based on the requirement of the drawing, most of the holes of the oil chamber cover plate are processed, the jig is used for clamping based on the hole position, the end face of the oil chamber cover plate is finished, and finally, the remaining unprocessed holes are finished.

[0028] Referring to Figure 3 The jig for processing each hole of the oil chamber cover plate is shown in the schematic diagram, after the part is clamped and pressed, the part is aligned and scribed, according to the requirements of the part drawing for each hole, a suitable tool (such as a drill bit, a milling cutter, a tap and the like) is selected, and each hole is processed to the requirement. The parameters are shown in the following table: Machining equipment Tool type Rotational speed (unit: r / s) Feed rate (unit: mm / r) Climb (unit: mm) GM100 K30 carbide drill 200-400 0-05-0-15 / GM100 K01 or K20 carbide end mill 300-600 0-08-0-2 / GM100 Carbide tap 50-150 / / Referring to the use Figure 5 , 6 , the jig for finishing the oil chamber cover plate is used to clamp the part, and the end face, the outer circle, the inner hole and the like of the part are finished to the requirement of the drawing. By using the jig, the shape and position tolerance requirements of the part end face and the inner hole can be effectively ensured. The parameters are shown in the following table: Figure 1 Machining equipment Tool type Rotational speed (unit: r / s) Feed rate (unit: mm / r) Climb (unit: mm) HTC63150 Tool holder (K01 rhombus insert of D or V type) 200-380 0-08-0-18 0-2-0-5 The part is turned over, and the jig for processing each hole of the oil chamber cover plate is referred to again Figure 5 , 6 ​Figure 7 is a schematic diagram of the clamping structure for machining holes in the oil chamber cover plate; the oil chamber cover plate is clamped, appropriate tools (such as drill bits, milling cutters, taps, etc.) are selected according to the requirements of the holes in the part drawing, and the holes are machined to the required specifications. The parameters are shown in the following table: Machining equipment Tool type Rotational speed (unit: r / s) Feed rate (unit: mm / r) Climb (unit: mm) GM100 K30 carbide drill 200-400 0-05-0-15 / GM100 K01 or K20 carbide end mill 300-600 0-08-0-2 / GM100 Carbide tap 50-150 / / In a second aspect, the present application also provides a machining clamp for reducing deformation of an oil chamber cover plate, which is applied to the machining method for reducing deformation of an oil chamber cover plate as described in the first aspect above, and characterized in that, The first clamp comprises a first gage block 20, a second gage block 21, a pressing plate 22, a hexagonal nut 23, a bolt 24, and a machine tool workbench 25. The first gage block 20 is arranged on the top of the machine tool workbench 25. The second gage block 21 is arranged on the top of the machine tool workbench 25. The pressing plate 22 is assembled on the end of the second gage block 21 away from the machine tool workbench 25. The hexagonal nut 23 is arranged on the side of the pressing plate 22 away from the second gage block 21. The bolt 24 cooperates with the hexagonal nut 23 and penetrates through the machine tool workbench 25. The second clamp comprises a pad 2, a first internal hexagonal cylindrical head screw 3, a cylindrical pin 4, a base 5, a stop lever 6, a second internal hexagonal cylindrical head screw 7, a positioning shaft 8, an elastic sleeve 9, a countersunk screw 10, and a third internal hexagonal cylindrical head screw 11. The stop lever 6 is arranged on one side of the base 5. The second internal hexagonal cylindrical head screw 7 is threadedly connected with the base 5 and penetrates through the stop lever 6. The pad 2 is assembled on the side of the base 5 away from the stop lever 6. The first internal hexagonal cylindrical head screw 3 is threadedly connected with the base 5 and penetrates through the pad 2. The positioning shaft 8 is arranged on the side of the pad 2 away from the base 5. The elastic sleeve 9 is arranged in the positioning shaft 8. The countersunk screw 10 is assembled on one side of the positioning shaft 8. The third internal hexagonal cylindrical head screw 11 is threadedly connected with the pad 2 and penetrates through the positioning shaft 8.

[0029] In the embodiment of the present application, the three first equal-height blocks 20 of the first clamp are placed on the machine tool worktable 25 to pad the oil chamber cover plate 1; the oil chamber cover plate 1 to be machined is placed on the planes of the three first equal-height blocks 20, and the positions of the three first equal-height blocks 20 are adjusted appropriately to avoid the positions of the holes to be machined; the three second equal-height blocks 21 are also placed on the machine tool worktable 25 to support the pressing plate 22 to press the part, and the height of the second equal-height block 21 can be adjusted according to the actual height of the part (the equal-height block is a machine tool machining component, and there are usually three equal-height blocks with different heights, and when a certain group of equal-height blocks cannot meet the required height, multiple blocks can be stacked to achieve the required height, and it is ensured that the height of the equal-height block is close to the height of the required pressing plane); the bolt 24 is placed in the T-shaped groove of the machine tool worktable 25 (the structure of the machine tool worktable 25 is different, and the size and length of the bolt 24 are adjusted according to the actual situation of the machine tool worktable 25), and passes through the waist-shaped hole between the pressing plates 22 and is locked by the hexagonal nut 23. The base 5 of the second clamp is designed with three installation notches of the pad block 2 and an installation groove of the stop lever 6; the pad block 2 is installed and fixed on the installation notch of the base 5 through the cylindrical pin 4 and the first internal hexagonal cylindrical head screw 3; the stop lever 6 is installed and fixed on the stop lever installation groove of the base 5 through the second internal hexagonal cylindrical head screw 7; the pad block 2 is designed with a positioning shaft installation groove and a screw hole, and the positioning shaft 8 is installed and fixed on the pad block 2 through the third internal hexagonal cylindrical head screw 11; the positioning shaft 8 is designed with an installation groove and a screw hole of the elastic sleeve 9, and the elastic sleeve 9 is installed on the positioning shaft 8 through the countersunk screw 10; the oil chamber cover plate 1 to be machined is aligned with the hole position and is installed on the clamp, and under the tightening of the countersunk screw 10, the diameter of the elastic sleeve 9 becomes larger, thereby expanding the installation hole of the oil chamber cover plate 1 to realize the clamping of the part. The material of the elastic sleeve 9 is 65Mn spring steel, and the cylindrical surface is provided with six openings. Under the pressure of the countersunk screw 10, the elastic sleeve 9 is easy to deform elastically, and the elastic deformation of the outer circle is large.

[0030] The above only discloses a preferred embodiment of the machining method and clamp for reducing the deformation of the oil chamber cover plate of the present application, and cannot be used to limit the scope of the rights of the present application. Those skilled in the art can understand that all or part of the processes of the above embodiment are implemented, and equivalent changes are made according to the claims of the present application, which still belongs to the scope covered by the present application.

Claims

1. A processing method for reducing deformation of an oil chamber cover plate, characterized in that, Includes the following steps: After the oil chamber cover plate is cast, stress relief treatment is carried out, the rough machining of the remaining parts is performed, and natural or artificial aging is carried out. Semi-finished oil chamber cover plate end face, outer circle and inner hole, eliminate deformed parts, and scribing the positional relationship between each hole; Based on the drawing requirements, most of the holes in the oil chamber cover plate are machined, and the end face of the oil chamber cover plate is finished by using a fixture based on the hole positions. Finally, the remaining unmachined holes are finished.

2. The processing method for reducing deformation of the oil chamber cover plate as described in claim 1, characterized in that, The stress treatment methods include heat treatment, vibration aging, and natural aging.

3. The processing method for reducing deformation of the oil chamber cover plate as described in claim 1, characterized in that, The natural aging process takes more than 20 days, while the artificial aging temperature is controlled at 500-550℃ and the holding time is 2 hours. The temperature is then cooled to below 200℃ in the furnace at a rate of ≤30℃ / h, and then the furnace is removed and air-cooled to room temperature.

4. A machining fixture for reducing deformation of an oil chamber cover plate, applied to the machining method for reducing deformation of an oil chamber cover plate as described in any one of claims 1-3, characterized in that, The device includes a first fixture and a second fixture. The first fixture includes a first leveling block, a second leveling block, a pressure plate, a hexagonal nut, a bolt, and a machine tool worktable. The first leveling block is disposed on the top of the machine tool worktable, and the second leveling block is disposed on the top of the machine tool worktable. The pressure plate is assembled on the end of the second leveling block away from the machine tool worktable. The hexagonal nut is disposed on the side of the pressure plate away from the second leveling block. The bolt and the hexagonal nut pass through the machine tool worktable. The second clamp includes a pad, a first hexagon socket head cap screw, a cylindrical pin, a base, a stop bar, a second hexagon socket head cap screw, a positioning shaft, an elastic sleeve, a countersunk screw, and a third hexagon socket head cap screw. The stop bar is located on one side of the base. The second hexagon socket head cap screw is threaded to the base and passes through the stop bar. The pad is assembled on the side of the base away from the stop bar. The first hexagon socket head cap screw is threaded to the base and passes through the pad. The positioning shaft is located on the side of the pad away from the base. The elastic sleeve is located inside the positioning shaft. The countersunk screw is assembled on one side of the positioning shaft. The third hexagon socket head cap screw is threaded to the pad and passes through the positioning shaft.

5. The processing method and fixture for reducing deformation of the oil chamber cover plate as described in claim 4, characterized in that, The elastic sleeve is made of 65Mn spring steel, and its cylindrical surface has six openings.

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