Pressure rolling device and levelling method for turning of monolithic box bottoms

Abstract

The application discloses a pressure rolling device and a leveling method for whole box bottom turning, relates to the field of box bottom processing, and adopts the pressure rolling device to press and level the whole box bottom, steps are as follows: S1: according to the difference between the end of the straight line section of the whole box bottom and the bottom of the whole box bottom, and the inner profile surface of the straight line section of the whole box bottom, fixing a small-end supporting device and a clamp on a workbench surface; S2: sleeving the inner profile surface of the whole box bottom on the clamp and the small-end supporting device; S3: making a roller press on the upper surface of the fork-shaped ring of the whole box bottom, and driving the whole box bottom to make rotary motion under the workbench surface, and driving the pressure rolling device to gradually feed downward, along the radial direction of the whole box bottom and close to the axis direction of the whole box body by the main shaft of the machine tool equipment. The method realizes fast clamping and precise leveling in the clamping process.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of box bottom processing, in particular to a pressure rolling device for turning of an integral box bottom and a leveling method. BACKGROUND

[0002] The integral box bottom has the characteristics of short manufacturing cycle and high reliability, and is a development direction of future box bottom processing. Due to the rotation characteristics, the commonly used machining method is turning. In order to ensure the wall thickness accuracy requirement of the box bottom processing, the clamping mode of the turning processing is particularly important. The clamping process not only needs to reduce the roundness and straightness deviation of the machined surface, but also needs to ensure the consistency of the front and rear references, which is extremely demanding.

[0003] When the inner surface is machined as a thickness reference, the turning process often adopts the way of adjusting the roundness and flatness of the inner surface by supporting the block tightly. The commonly used way is four-point pressing method, that is, the part is uniformly pressed into the jig by using four symmetrical points, and the flatness is adjusted. However, this method has the following shortcomings:

[0004] 1. The pressing amount is difficult to control, and the pressing process is time-consuming and laborious, with high labor intensity;

[0005] 2. It is difficult to level, and once the integral box bottom is pressed into the jig, it is difficult to level due to the limitation of the axial supporting force, which affects the consistency of the reference.

[0006] During the process of pressing the inner surface of the integral box bottom into the jig, the existing method needs to use 3-4 operators to gradually press down at multiple points by using hammer, hammer and pressure, and finally press the box bottom into the turning jig for turning. This method has the following problems:

[0007] 1. Low clamping accuracy, this adjustment method is difficult to control the pressing amount and has poor flatness after pressing, which cannot guarantee the consistency of the front and rear references, and is easy to indirectly cause the wall thickness to be out of tolerance.

[0008] 2. Poor surface quality, since the pressing is carried out in a violent way, the surface is often caused to have many pits and deformations during the pressing process.

[0009] 3. Complicated personnel operation, in order to ensure the correct and uniform pressing process and prevent the product from being skewed, stuck or even deformed, 4 people need to cooperate to operate, 2 people to press down, 1 person to measure the pressing amount and observe the state, and 1 person to adjust the height of the tooling. The operation process is complicated.

[0010] 4. Low processing efficiency, long pressing time, low clamping efficiency, and the average pressing time is 4 hours * 4 people. SUMMARY

[0011] The technical problems solved by the present application are: overcoming the deficiencies of the prior art, providing a pressure rolling device and a leveling method for turning a whole box bottom, aiming at the clamping requirement in the turning process of the whole box bottom formed by spinning, solving the problems of low reliability, poor leveling accuracy and low operation efficiency in the conventional tire mounting process, and realizing rapid tire mounting and accurate leveling during the clamping process.

[0012] The technical solution of the present application is:

[0013] A pressure rolling device for turning a whole box bottom, comprising a fixed end, a sleeve, a spring and a roller; the fixed end is detachably connected to the main shaft of a machine tool device, the fixed end is fixedly connected with an inner cylinder, the sleeve is coaxially sleeved on the outer side of the inner cylinder and is slidingly connected with the inner cylinder along the axial direction of the inner cylinder, the spring is located inside the inner cylinder, the inner cylinder is provided with a waist-shaped hole along the axial direction of the inner cylinder, the inner cylinder is connected with a positioning bolt, the positioning bolt passes through the waist-shaped hole, and the roller is rotationally connected to one end of the sleeve away from the inner cylinder, and the rotation axis of the roller is perpendicular to the axis of the sleeve.

[0014] The elastic deformation limit of the spring is 30%-50% of the load of the main shaft of the machine tool device.

[0015] The fixed end is connected with the spring through the inner sleeve to form a guide connection, and the front end rigid clamping end is rigidly connected with the main shaft tool holder through a screw fastening.

[0016] A leveling method using the above-mentioned pressure rolling device for turning a whole box bottom, comprising:

[0017] S1: according to the difference between the straight line segment end of the whole box bottom and the bottom of the whole box bottom, and the inner profile of the straight line segment of the whole box bottom, fixing a small end support device and a mold on the workbench surface;

[0018] S2: the inner profile of the whole box bottom is sleeved outside the mold and the small end support device;

[0019] S3: the roller is pressed on the upper surface of the fork-shaped ring of the whole box bottom, the whole box bottom is rotated under the driving of the workbench surface, and the main shaft of the machine tool device drives the pressure rolling device to gradually feed downward along the radial direction of the whole box bottom and close to the axial direction of the whole box body.

[0020] The following steps are performed before step S3,

[0021] The pressure rolling device is installed on the main shaft of the machine tool, and the X and Z origins of the pressure rolling device are aligned, the Z direction is the vertical direction, and the X direction is the radial direction of the whole box bottom.

[0022] The step S3 includes,

[0023] S31: Lower the lathe beam to increase the rigidity of the main shaft, calculate the fitting gap according to the actual size of the inner surface and the size of the mold surface, and estimate the single pressing amount according to the initial setting of the tire pressing amount up and down floating according to the fitting gap;

[0024] S32: According to the single pressing amount, pre-pressing is performed;

[0025] S33: After pre-pressing, observe the main shaft load of the machine tool panel. When the main shaft load is greater than 15%, modify the pre-pressing parameters and repeat step S32. When the initial pressing main shaft load is less than 15%, proceed to the next step;

[0026] S34: According to the parameters of pre-pressing, rough pressing is performed until the remaining pressing amount is not greater than the required flatness, and accurate pressing is started.

[0027] During the rough pressing process, the overall box bottom speed is 1-2r / min, the X-direction feed is 1-2mm / r, the Z-direction feed is 0.3-0.5mm / r, and the pre-pressing amount is 6-10mm.

[0028] During the accurate pressing process, the X-direction feed and the Z-direction feed are gradually reduced, and after the value of the Z-direction feed speed is not greater than the required flatness, constant Z value is used for repeated pressing.

[0029] The constant Z value is the Z coordinate value of the lowest point of the upper surface of the fork-shaped ring after accurate pressing.

[0030] In step S34, after the flatness of the overall box body reaches the required flatness, a ring groove is provided on the outside of the straight section of the overall box bottom, the pressing device is clamped in the ring groove, and the pressing device and the workbench are fixed to press the overall box bottom vertically downward.

[0031] In summary, the present application has at least the following beneficial technical effects:

[0032] The clamping roundness and flatness during the turning process of the overall box bottom directly determine the turning accuracy. The traditional clamping and pressing method has low reliability and poor alignment accuracy, and cannot meet the turning accuracy of the overall box bottom. Therefore, a pressure-adjustable rolling device is designed, and a machine clamping and leveling method and parameter setting method are proposed based on the device, which can improve the efficiency and accuracy of the overall box bottom turning leveling and ensure that the clamping and leveling accuracy is within 0.05mm. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Fig. 1 is a schematic diagram of the principle of the spring pressure control device in the embodiment of the present application;

[0034] Figure 2 a and Figure 2 b are the overall structure schematic diagram and the exploded structure schematic diagram of the spring pressure control device in the embodiment of the present application;

[0035] Figure 3 Fig. 1 is a schematic view of the inner surface clamping device in the embodiment of the present application;

[0036] Figure 4 Fig. 2 is a schematic view of the spring pressure control device pressing the box bottom into the mold in the embodiment of the present application;

[0037] Figure 5 Fig. 3 is a flow chart of the spring pressure control device pressing the box bottom in the embodiment of the present application.

[0038] Reference signs: 1, overall box bottom;

[0039] 21, fixed end; 22, inner cylinder; 23, sleeve; 24, spring; 25, roller; 26, positioning bolt;

[0040] 31, conical bottom support aluminum block; 32, small end support device; 33, pressing device. DETAILED DESCRIPTION

[0041] The present application will be further described in detail below in combination with the drawings and specific embodiments:

[0042] The embodiment of the present application discloses a pressure rolling device and leveling method for turning the overall box bottom, like Figure 1 and Figure 2 As shown in a and b, a pressure-adjustable rolling device in the machine is designed by using a numerical control lathe, the rolling device includes a fixed end 21, a sleeve 23, a spring 24, and a roller 25; the fixed end 21 is detachably connected to the main shaft of the machine tool equipment, the fixed end 21 is fixedly connected with an inner cylinder 22, the sleeve 23 is coaxially sleeved outside the inner cylinder 22 and is slidably connected with the inner cylinder 22 along the axial direction of the inner cylinder 22, the spring 24 is located inside the inner cylinder 22, the sleeve 23 is provided with a waist-shaped hole along the axial direction of the inner cylinder 22, the inner cylinder 22 is connected with a positioning bolt 26, the positioning bolt 26 penetrates through the waist-shaped hole, and the roller 25 is rotationally connected to one end of the sleeve 23 away from the inner cylinder 22, and the rotation axis of the roller 25 is perpendicular to the axial line of the sleeve 23. The fixed end 21 forms a rigid connection system with the main shaft tool rest through screw fastening of the front end rigid clamping end.

[0043] Since the product demand is to be pressed in the machine state, the pressure of the device mainly comes from the machine tool equipment. In order to avoid the overload of the main shaft of the machine tool equipment in the pressing process, a spring 24 pressure control system is designed. The selection process of the spring 24 is designed according to the 30% principle of the load of the main shaft of the machine tool equipment. In the pressing process, the reaction force generated by the product on the device is transmitted to the main shaft through the spring 24, and the main shaft load requirement can be met within the elastic deformation range of the spring 24. At the same time, the compression amount of the spring 24 can be visualized vertically to visualize the pressure value for the purpose of adjusting subsequent parameters.

[0044] The sleeve 23 and the inner cylinder 22 work together to provide guidance, and the connection between the fixed end 21 and the spindle achieves an overall rigid connection. The guiding system and the overall rigid system constitute the guiding system, and the fixed end 21, the spindle, and the connection structure between them constitute the overall rigid system. This device is rigidly connected to the machine tool spindle through the guiding system and the overall rigid system, and transmits the spindle pressure to the workpiece.

[0045] Roller 25 directly contacts the surface of the integral box bottom 1 and transmits the tire pressing pressure. During the tire pressing process, the rotational motion of the machine tool, the relative rotation of roller 25, and the feed motion of the Z-axis constitute the tire pressing motion. The design of roller 25 introduces relative sliding between roller 25 and the product, avoiding dry grinding during the tire pressing process and greatly improving surface quality. At the same time, by adjusting the machine tool speed, setting the Z-axis feed, and determining the pressing width of roller 25, a mature and efficient set of tire pressing combination parameters was designed and verified.

[0046] Leveling methods include:

[0047] S1: Based on the drop between the end of the straight section of the overall box bottom 1 and the bottom of the overall box bottom 1, and the inner shape of the straight section of the overall box bottom 1, fix the small end support device 32 and the jig on the workbench.

[0048] S2: The inner surface of the overall box bottom 1 is fitted over the jig and small end support device 32;

[0049] Install the pressure rolling device on the machine tool spindle and align the origin of the pressure rolling device in the X and Z directions. The Z direction is the vertical direction and the X direction is the radial direction along the bottom 1 of the integral box.

[0050] S31: Lower the lathe crossbeam to increase spindle rigidity. Calculate the clearance based on the measured dimensions of the inner surface and the dimensions of the fixture. Estimate the single-cycle tire pressure based on the clearance, adjusting it slightly above or below the initial set tire pressure. Specifically, the difference between the fixture dimensions and the measured inner surface dimensions is the clearance. There is a precise correspondence between the set tire pressure and the clearance. When the set tire pressure is 10mm, the clearance is 0.05mm. When estimating the single-cycle tire pressure using the initial set tire pressure of 10mm, if the clearance is greater than 0.05mm, increase the initial set tire pressure based on experience to obtain the single-cycle tire pressure (i.e., the single-cycle tire pressure value is greater than 10mm). If the clearance is less than 0.05mm, decrease the initial set tire pressure based on experience to obtain the single-cycle tire pressure (i.e., the single-cycle tire pressure value is less than 10mm).

[0051] S32: According to the single pressing amount, pre-pressing is carried out, and during pre-pressing, the roller is arranged on the upper surface of the fork-shaped ring of the overall box bottom, and the overall box bottom is rotated under the driving of the workbench surface;

[0052] S33: After pre-pressing, the spindle load condition of the machine tool panel is observed, and when the spindle load is greater than 15%, the pre-pressing parameters are modified and step S32 is repeated until the initial pressing spindle load is less than 15%, and then the next step is carried out;

[0053] S34: According to the pre-pressing parameters, rough pressing is carried out, and during rough pressing, the spindle of the machine tool equipment drives the pressure rolling device Z to gradually feed downward and along the X direction and close to the overall box axis direction, until the remaining pressing amount is not greater than the required flatness, and then accurate pressing is started. During accurate pressing, the X direction feed and the Z direction feed are gradually reduced, and after the value of the Z direction feed speed is not greater than the required flatness, constant Z value repeated pressing is adopted, and the constant Z value is the Z coordinate value of the lowest point of the upper surface of the fork-shaped ring after accurate pressing.

[0054] After the flatness of the overall box body reaches the required flatness and the top of the small end support device 32 contacts the top of the inner surface of the overall box bottom 1, the tire pressing is completed, and then the overall loudness is fixed on the workbench surface. The fixing step includes: the linear segment outside of the overall box bottom 1 is provided with a ring groove, the pressing device 33 is clamped in the ring groove, and the pressing device 33 is fixed with the workbench surface, so that the pressing device 33 vertically presses the overall box bottom 1 on the workbench surface, at this time the overall box body has high leveling accuracy and is stably fixed on the workbench surface, so that the subsequent outer surface machining has accurate machining reference.

[0055] The main technology of the leveling method is as shown in Figure 3 After the inner surface turning process of the overall spinning box bottom, the next process is to clamp the overall box body by using a clamping device, and the clamping reference is the machined inner surface. The clamping device includes a jig and a small end support device 32. The jig is a conical bottom support aluminum block 31, which is milled according to the shape of the inner surface of the overall box body. The height of the small end support device 32 is set according to the difference between the linear segment end of the overall box bottom 1 and the bottom of the overall box bottom 1, and the jig and the small end support device 32 are fixed to the workbench surface. The conical bottom support aluminum block 31 is used for inner surface clamping to ensure good roundness and flatness. The spinning bottom leveling method based on the pressure adjustable rolling device provided by the patent can ensure that the clamping leveling accuracy is within 0.05mm.

[0056] As shown in Figure 4As shown, the device is clamped on the machine tool spindle and the device X, Z origin is aligned. Using the rotary motion of the lathe, combined with the X, Z feed motion, the two directions of micro-feeding are realized, the pressing force is provided by the machine tool spindle, and the roller 25 and the box bottom step surface form relative sliding, that is, the automatic tire pressing process is realized. The setting of the tire pressing amount is determined by the Z direction feed value, the pressing force is determined by the Z direction and X direction feed, and the spring 24 extension amount provides buffer to avoid the impact of rigid pressing on the spindle.

[0057] The alignment process based on the device is as shown in Figure 5 First, the lathe beam is lowered to increase the rigidity of the spindle, and then the single pressing amount is estimated, which can be tested by pressure and observation of the pressure mark. Secondly, the X, Z feed program is compiled, and the rotation speed, axial feed is set, and the coarse pressing is carried out until the remaining pressing amount is less than 1mm. During the precise pressing process, the feed is continuously reduced, and finally the constant Z value is repeatedly pressed to ensure the flatness and realize the leveling.

[0058] Main technology three: the clamping method principle of the whole box bottom 1 provided by the patent is to use the spindle rigidity to press the box bottom. In order to protect the machine tool and the product, each parameter in the pressing process is important, therefore, the patent provides various parameters of the spinning forming whole box bottom tire pressing based on the device, the table is the coarse pressing parameter, see the table below.

[0059]

[0060] Although the present application is disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application, therefore, the protection scope of the present application should be limited by the scope defined by the claims of the present application.

Claims

1. A method of surfacing using a pressure rolling device for turning of monolithic box bottom, characterized in that: The pressure rolling device comprises a fixed end (21), a sleeve (23), a spring (24) and a roller (25); The fixed end (21) is detachably connected to the main shaft of the machine tool equipment, and the fixed end (21) is fixedly connected with an inner cylinder (22); the sleeve (23) is coaxially sleeved outside the inner cylinder (22) and is slidably connected with the inner cylinder (22) along the axial direction of the inner cylinder (22); the spring (24) is located inside the inner cylinder (22); the sleeve (23) is provided with a waist-shaped hole along the axial direction of the inner cylinder (22); the inner cylinder (22) is connected with a positioning bolt (26), the positioning bolt (26) penetrates through the waist-shaped hole; and the roller (25) is rotatably connected to one end of the sleeve (23) away from the inner cylinder (22). The leveling method comprises: S1: according to the difference between the end of the straight line segment of the overall box bottom (1) and the bottom of the overall box bottom (1), the inner shape surface of the straight line segment of the overall box bottom (1), Fixing the small-end supporting device (32) and the mold on the workbench surface; S2: sleeving the inner shape surface of the overall box bottom (1) outside the mold and the small-end supporting device (32); installing the pressure rolling device on the main shaft of the machine tool, and aligning the X and Z origins of the pressure rolling device, wherein the Z direction is the vertical direction and the X direction is along the radial direction of the overall box bottom (1); S3: making the roller (25) press on the upper surface of the fork-shaped ring of the overall box bottom (1), and making the overall box bottom (1) rotate under the driving of the workbench surface, and gradually feeding the pressure rolling device downward along the radial direction of the overall box bottom (1) and close to the axial direction of the overall box bottom; Step S3 comprises, S31: lowering the lathe beam to increase the rigidity of the main shaft, calculating the fitting gap according to the actual measured size of the inner shape surface and the size of the mold surface, and floating up and down according to the initial setting of the tire pressing amount to estimate the single tire pressing amount; S32: pre-pressing according to the single tire pressing amount; S33: after pre-pressing, observing the main shaft load of the machine tool panel, when the main shaft load is greater than 15%, modifying the pre-pressing parameters and repeating step S32, until the initial pressing main shaft load is less than 15%, and then proceeding to the next step; S34: rough pressing according to the pre-pressing parameters until the remaining pressing amount is not greater than the required flatness, and then starting precise pressing; during the rough pressing process, the main shaft of the machine tool drives the pressure rolling device to gradually feed downward in the Z direction and gradually feed along the X direction and close to the axial direction of the overall box bottom until the remaining pressing amount is not greater than the required flatness, and then starting precise pressing; during the precise pressing process, the X direction feed and the Z direction feed are gradually reduced, and after the value of the Z direction feed speed is not greater than the required flatness, constant Z value is used for repeated pressing.

2. A method of leveling according to claim 1, wherein: The elastic deformation limit of the spring (24) is 30%-50% of the load of the main shaft of the machine tool equipment.

3. The method of claim 1, wherein: The fixed end (21) is connected with the spring (24) through the inner cylinder (22) to form a guide connection, and is rigidly connected with the main shaft tool rest through screw fastening of the front end rigid clamping end to form a rigid connection system.

4. The method of claim 1, wherein: In the rough pressing process, the rotating speed of the whole box bottom (1) is 1-2 r / min, the X-direction feed is 1-2 mm / r, the Z-direction feed is 0.3-0.5 mm / r, and the pre-pressing amount of the tire is 6-10 mm.

5. The method of claim 1, wherein: In the accurate pressing process, the X-direction feed and the Z-direction feed are gradually reduced, and after the value of the Z-direction feed speed is not greater than the required flatness, the constant Z value is repeatedly pressed.

6. A method of levelling according to claim 5 wherein: The constant Z value is the Z coordinate value of the lowest point of the upper surface of the fork-shaped ring after accurate pressing.

7. The method of claim 1, wherein: In the step S34, after the flatness of the whole box bottom reaches the required flatness, a ring groove is arranged outside the straight line segment of the whole box bottom (1), the pressing device (33) is clamped in the ring groove, and the pressing device (33) and the workbench are fixed to press the whole box bottom (1) vertically downward.

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