Multifunctional combined vertical grinding machine with tail end rotary support tailstock structure

Abstract

The present application relates to a kind of multifunctional composite vertical grinding machine with tail end rotary support center structure, including bed, column, rotary worktable mounted on bed, main shaft box with grinding wheel;The main shaft box is connected with the inside of column by horizontal and vertical composite driving guide mechanism, characterized in that: it further includes tail end rotary support center structure;Rotary support center structure is vertically installed above rotary worktable by center support mechanism;When processing shaft parts, rotary support center structure is aligned with rotary worktable center.This application increases center structure on vertical grinding machine, through the cooperation of center structure and rotary worktable, it can realize the positioning of shaft parts on vertical grinding machine, increases the grinding function of long shaft, combines the function of high-precision cylindrical grinder on the equipment, so as to realize the function of vertical grinding and cylindrical grinding through one equipment.

Description

Technical Field

[0001] This invention pertains to grinding machine tools, and specifically relates to a multifunctional composite vertical grinding machine with an added tail-end rotary support center structure. Background Technology

[0002] The conventional function of existing vertical grinding machines is to grind the end faces, outer diameters, and inner holes of relatively flat parts. However, it is impossible to machine long shaft parts on traditional vertical grinding machines. Precision machining of long shaft parts generally needs to be completed on high-precision cylindrical grinding machines. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing equipment and combine the functions of a high-precision cylindrical grinding machine. By providing a tail-end rotary support center structure, a multi-functional composite vertical grinding machine can be realized on a single machine to perform grinding of the end face, outer circle, and inner hole of flat parts, as well as grinding of shaft parts.

[0004] One of the above-mentioned objectives of the present invention is achieved through the following technical solution:

[0005] A multifunctional composite vertical grinding machine with an added tail-end rotary support tip structure includes a bed, a column, a rotary worktable mounted on the bed, and a spindle box with a grinding wheel installed. The spindle box is connected to the column through a horizontal and vertical composite drive guide mechanism. The machine is characterized by further including a tail-end rotary support tip structure. The rotary support tip structure is vertically mounted above the rotary worktable through a tip support mechanism. When machining shaft-type parts, the rotary support tip structure is aligned with the center of the rotary tooling table.

[0006] Furthermore: The vertical grinding machine is equipped with two spindle boxes, which are arranged left and right; one of the spindle boxes provides a mounting surface for the rotary support tip structure, which is mounted on the side wall of the spindle box through a tip support mechanism; the rotary support tip structure is linked with the horizontal and vertical composite drive guide mechanism of the spindle box.

[0007] Furthermore: the top support mechanism includes a top housing, a top bracket, and a top drive cylinder; the top housing is fixed above the column in a cantilevered manner, the rear end of the top bracket is connected to the front end of the top housing through a vertically arranged guide rail pair, and the top drive cylinder is fixedly installed on the top housing; the top structure is vertically installed on the top bracket and driven by the top drive cylinder.

[0008] Furthermore: the top support mechanism includes a small support column, a top bracket, and a top drive cylinder; the small support column is vertically fixedly installed on the bed, and the inner side of the small support column is connected to the top bracket through a vertically arranged guide rail pair; the top drive cylinder is fixedly installed on the upper end of the bed or the upper end of the small support column; the top structure is vertically installed on the top bracket and is driven by the top drive cylinder.

[0009] Furthermore: the top support mechanism is located on the side of the spindle box, and includes a top support bracket and a second transverse and longitudinal composite drive guide mechanism. The top is vertically mounted on the top support bracket, and the top support bracket is connected to the column through the second transverse and longitudinal composite drive guide mechanism.

[0010] Furthermore: the rotary table adopts a hydrostatic rotary table structure, the center structure adopts a hydrostatic center, and the grinding wheel is mounted on the spindle box via a hydrostatic spindle.

[0011] Furthermore: the hydrostatic center includes a shaft frame and a center shaft inserted into the shaft frame. The shaft frame is connected to the center support mechanism. The center head of the center shaft extends from the lower end of the shaft frame, and the tail end of the center shaft extends from a tail end cap fixed to the tail end of the shaft frame. A pressure-bearing oil groove is formed on the outer ring surface of the center shaft inside the shaft frame. An oil inlet passage is formed on the center shaft, connecting each pressure-bearing oil groove with the tail end of the center shaft. A pressure-bearing oil cavity is formed between the pressure-bearing oil groove and the inner bore surface of the shaft frame, so that the center shaft is installed in the shaft frame by means of hydrostatic bearing support. An oil return hole for hydrostatic oil output is provided on the side wall of the shaft frame.

[0012] A front oil seal structure is provided between the front end of the shaft bracket and the center shaft, and a tail oil seal structure is provided at the mating part of the tail end cover and the center shaft; an axial clamping mechanism is provided at the tail end of the center shaft to press the center head onto the workpiece.

[0013] Furthermore: the pressure-bearing oil grooves set on the center shaft are one or more sets arranged symmetrically, and each pressure-bearing oil groove is provided with a throttling zone. The throttling zone is provided with an oil inlet hole and connected to the oil inlet passage. The throttling zone of each pressure-bearing oil groove is connected to the part outside the throttling zone of another pressure-bearing oil groove in the same group through a feedback oil passage built into the center shaft. The feedback oil passage connects the two symmetrically arranged pressure-bearing oil grooves to form a static pressure circulation oil passage.

[0014] Furthermore: a piston chamber is provided at the tail end of the shaft bracket, and a piston head is provided at the tail end of the center shaft. The piston head and the piston chamber form a piston engagement. An oil hole is provided on the tail end or the side of the tail end of the shaft bracket. The oil hole communicates with the piston chamber, forming a hydraulic cylinder-type axial clamping mechanism that acts on the center shaft.

[0015] The advantages and positive effects of this invention are as follows:

[0016] 1. This invention adds a center structure to a vertical grinding machine. Through the cooperation of the center structure and the rotary table, shaft-type parts can be positioned and installed on the vertical grinding machine, increasing the grinding function of long shafts and combining the functions of a high-precision cylindrical grinding machine into this equipment, thereby realizing the functions of vertical grinding and cylindrical grinding in one machine.

[0017] 2. The present invention preferably combines a hydrostatic rotary table, a hydrostatic center and a hydrostatic grinding spindle into a vertical grinding machine, which can greatly improve the grinding accuracy of the vertical grinding machine. Theoretically, the grinding accuracy can reach 0.1μm.

[0018] 3. This vertical grinding machine is arranged vertically when grinding shaft parts. The vertical arrangement transfers the effect of gravity to a direction that is not related to the machining accuracy, which overcomes the problem of machining accuracy being affected by gravity deformation when the axis is placed horizontally. This is beneficial to improving the grinding accuracy of shaft parts.

[0019] 4. The center structure added to this vertical grinding machine is located in the idle space of the equipment. Therefore, although the grinding function of shaft parts is added, the floor area of ​​the equipment does not change.

[0020] 5. The preferred tip structure of the present invention is a hydrostatic tip. Due to the presence of an oil film in the moving parts of the hydrostatic tip structure, it has the characteristics of high rotational accuracy and can maintain its accuracy with almost no attenuation. At the same time, the hydrostatic oil film has good vibration absorption performance, which can greatly improve the surface finish of the parts. The surface finish of the parts can be improved by at least half a grade (accuracy level).

[0021] 6. The preferred tip structure of the present invention is a hydrostatic tip. The small size of the hydrostatic tip results in a small distance between the spindle box and the outer side of the tip, thus allowing the grinding wheel to be used to its smallest size, thereby improving the utilization rate of the grinding wheel. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the first embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the second embodiment of the present invention;

[0024] Figure 3 This is a structural schematic diagram of the third embodiment of the present invention;

[0025] Figure 4 This is a structural schematic diagram of the fourth embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the fifth embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of the sixth embodiment of the present invention;

[0028] Figure 7 This is a cross-sectional view of the hydrostatic tip of the present invention;

[0029] Figure 8 This is an external view of the top shaft of the present invention. Detailed Implementation

[0030] The structure of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these embodiments are descriptive and not limiting.

[0031] A high-precision vertical grinding machine with a center-mounted structure, please see [link / reference]. Figure 1-6 It mainly includes a bed 1, a column 6, a rotary worktable 2 mounted on the bed, and a spindle box 3 equipped with a grinding wheel; the spindle box is connected to the column through a horizontal and vertical composite drive guide mechanism 5. Its invention point is: it also includes a tail end rotary support center structure 4; the rotary support center structure is vertically mounted above the rotary worktable through a center support mechanism; when machining shaft parts, the rotary support center structure is aligned with the center of the rotary tooling table, the upper end of the workpiece is positioned by the rotary support center structure, and the lower end of the workpiece is fixed by the rotary tooling table.

[0032] The tip structure can be installed on a vertical grinding machine in six ways, with method one being the most preferred installation method for the tip structure of this invention.

[0033] Method 1: Dual spindle boxes - side-mounted center

[0034] See Figure 1 The vertical grinding machine is equipped with dual spindle boxes. In one configuration, a large grinding wheel can be used to machine large workpieces, while a small grinding wheel can be used to machine small internal holes. In another configuration, one spindle box can be used for coarse grinding, and the other for fine grinding, each suitable for different machining processes. The rotary support center structure is mounted on the side wall of one of the spindle boxes via a center support mechanism. The rotary support center structure is linked to the horizontal and vertical composite drive guide mechanism of that spindle box, enabling precise adjustment and positioning of the rotary support center structure. This mounting method eliminates the need for a separate center support mechanism on the vertical grinding machine, simplifying the structure of this high-precision vertical grinding machine and minimizing production costs, thus achieving maximum efficiency with minimal investment.

[0035] Method 2: Single spindle box - side-mounted center

[0036] See Figure 2 Based on method one, the spindle box on one side is removed, but the horizontal and vertical composite drive guide mechanism (the second horizontal and vertical composite drive guide mechanism mentioned in the invention) is retained. The top structure is directly installed on the front vertical plate of the composite drive guide mechanism.

[0037] Method 3: Dual spindle boxes - top-mounted center

[0038] See Figure 3 The vertical grinding machine is equipped with dual spindle boxes. The center structure adopts a horizontal arm mounting form and is installed between the two spindle boxes. Specifically, the center support mechanism includes a center box 7, a center bracket 9, and a center drive cylinder 8. The center box is fixed above the column in a cantilevered manner. The rear end of the center bracket is connected to the front end of the center box through a vertically set guide rail pair. The center drive cylinder is fixedly installed on the center box. The center structure is vertically installed on the center bracket and driven by the center drive cylinder.

[0039] Method 4: Dual spindle box - small column mounting center

[0040] See Figure 4 The vertical grinding machine is equipped with dual spindle boxes. The center structure adopts a separate small support column installation form, with the small support column positioned offset to one side in front of the dual spindle boxes. Specifically, the center support mechanism includes a small support column 10, a center bracket 12, and a center drive cylinder 11. The small support column is vertically fixedly installed on the machine bed, and the inner side of the small support column is connected to the center bracket via a vertically arranged guide rail pair. The center drive cylinder is fixedly installed on the upper end of the machine bed or the upper end of the small support column. The center structure is vertically installed on the center bracket and driven by the center drive cylinder.

[0041] Method 5: Single spindle box - top-mounted center

[0042] See Figure 5 The vertical grinding machine is equipped with only one spindle box. The center structure adopts a horizontal arm mounting form and is installed on the side of the spindle box. Specifically, the center support mechanism includes a center box body 7, a center bracket 9, and a center drive cylinder 8. The center box body is fixed above the column in a cantilevered manner. The rear end of the center bracket is connected to the front end of the center box body through a vertically set guide rail pair. The center drive cylinder is fixedly installed on the center box body. The center structure is vertically installed on the center bracket and driven by the center drive cylinder.

[0043] Method Six: Single Spindle Box - Small Column Mounting Center

[0044] See Figure 6The vertical grinding machine is equipped with only one spindle box, and the center structure adopts a separate small support column installation form, which is located in front of the spindle box and offset to one side. Specifically: the center support mechanism includes a small support column 10, a center bracket 12, and a center drive cylinder 11; the small support column is vertically fixedly installed on the machine bed, and the inner side of the small support column is connected to the center bracket through a vertically arranged guide rail pair; the center drive cylinder is fixedly installed on the upper end of the machine bed or the upper end of the small support column; the center structure is vertically installed on the center bracket and driven by the center drive cylinder.

[0045] The tip structure of this invention can employ existing dead tips and ordinary bearing-supported live tips. In this invention, the tip structure preferably employs a hydrostatic tip. See [link to relevant documentation]. Figure 7 and 8 The hydrostatic center is a novel type of live center structure supported by a liquid hydrostatic bearing, which is also one of the innovations of this invention. Its main structural features are as follows:

[0046] The hydrostatic center includes a shaft frame 4.2 and a center shaft 4.1 inserted into the shaft frame. The shaft frame is connected to the center support mechanism. The shaft frame can be an integral part of the center support, or it can be processed separately and then assembled. The center head 4.1.1 of the center shaft extends from the lower end of the shaft frame, and the tail end of the center shaft extends from the tail end cap 4.3 fixed to the tail end of the shaft frame. A pressure-bearing oil groove 4.13 is formed on the outer ring surface of the center shaft inside the shaft frame. An oil inlet passage 4.9 is formed on the center shaft, connecting each pressure-bearing oil groove with the tail end of the center shaft. A pressure-bearing oil cavity is formed between the pressure-bearing oil groove and the inner hole surface of the shaft frame, so that the center shaft is installed in the shaft frame by means of hydrostatic bearing support. An oil return hole 4.2.1 for hydrostatic oil output is provided on the side wall of the shaft frame.

[0047] The aforementioned pressure oil tank is further equipped with a throttling structure, which can be implemented in two ways:

[0048] Method 1: Employing a non-feedback throttling structure, specifically including a throttling device, which can be a small-hole throttling device or a capillary throttling device, etc. The specific structure and working principle of the small-hole throttling device or capillary throttling device are based on existing technology. The throttling device is built into the oil inlet circuit of the bearing oil tank, allowing the incoming oil to flow into the pressure oil tank through the throttling device.

[0049] Method 2: Employing a built-in feedback throttling structure. Specifically: One or more sets of pressure-bearing oil grooves are symmetrically arranged on the center shaft. Each pressure-bearing oil groove has a throttling zone 4.14, with an oil inlet 4.15 connected to the oil inlet passage. Each pressure-bearing oil groove's throttling zone has a feedback oil inlet 4.16, which is connected to the portion outside the throttling zone of another pressure-bearing oil groove in the same group via a feedback oil passage 4.10 built into the center shaft. This feedback oil passage connects the two symmetrically arranged pressure-bearing oil grooves, forming a hydrostatic circulation oil passage. Further, it is preferable that two sets of pressure-bearing oil grooves are provided on the center shaft, see [reference]. Figure 8 Two sets of pressure-bearing oil grooves are arranged vertically along the axial direction of the center shaft, with the upper set and the lower set staggered in the circumferential direction. Since the center shaft is typically a slender shaft, this staggered arrangement of the two sets of pressure-bearing oil grooves facilitates the layout and machining of the pressure-bearing oil grooves and internal feedback oil circuits. Furthermore, it ensures the formation of a uniform hydrostatic oil film throughout the circumference, thereby precisely guaranteeing the coaxiality of the center shaft and the shaft support. Theoretically, this can achieve a rotational accuracy of 0.1 μm for the hydrostatic center.

[0050] For this preferred built-in feedback throttling method, the preferred oil return structure is as follows:

[0051] Axial oil return grooves 4.11 are provided between the two oil grooves of the upper set of pressure-bearing oil grooves and between the two oil grooves of the lower set of pressure-bearing oil grooves on the outer ring surface of the center shaft. A circumferential oil return groove 4.12, which communicates with all the axial oil return grooves, is provided between the upper and lower sets of pressure-bearing oil grooves on the outer ring surface of the center shaft. When the center shaft is in the axially clamped state, the circumferential oil return groove is aligned and communicates with the oil return hole on the shaft bracket.

[0052] A front oil seal is installed between the shaft support and the center shaft near the front end, and a rear oil seal is installed at the mating point between the rear end cover and the center shaft. The front and rear oil seals can employ, but are not limited to, the sealing rings shown in the attached diagram. These front and rear oil seals prevent oil entering the pressure-bearing oil groove from flowing out from both ends of the center shaft, which is essential for establishing static pressure between the shaft support and the center shaft.

[0053] An axial clamping mechanism is provided at the tail end of the center shaft to press the center head against the workpiece. The axial clamping mechanism can be implemented by adding a separate structure to the tail end of the center shaft, such as by adding a hydraulic cylinder or pneumatic cylinder. Alternatively, the axial clamping mechanism can be implemented by setting a mating structure between the tail end of the center shaft and the tail end of the shaft holder. In this invention, the preferred embodiment of the axial clamping mechanism is as follows:

[0054] A piston chamber 4.7 is located at the tail end within the shaft bracket, and a piston head 4.8 is located near the tail end of the center shaft. The piston head can be integrally formed onto the center shaft, and the piston head and piston chamber form a piston fit. An oil hole 4.6 is formed on the end cover or the side of the tail end of the shaft bracket, communicating with the piston chamber. The oil hole is connected to the oil supply device through an external oil pipe, forming a hydraulic cylinder-type axial clamping mechanism acting on the center shaft. To simplify the external oil circuit and achieve rapid reset of the center shaft, a shaft end head 4.4 is fitted onto the rear extended end of the center shaft, and a reset spring 4.5, fitted onto the center shaft, is press-fitted between the shaft end head and the end cover.

[0055] The main characteristics of this static pressure center are:

[0056] 1. It has high support stiffness, which can reach 6 times that of the top of a rolling support, reaching the level of a dead top.

[0057] 2. High rotational accuracy, achieving a rotational accuracy higher than that of the original part; the rotational accuracy of the machined workpiece can be about one level higher than that of the machine tool.

[0058] 3. Theoretically, it has zero wear and good precision retention.

[0059] In this invention, the rotary table preferably adopts a hydrostatic rotary table structure, and the grinding wheel is preferably mounted on the spindle box via a hydrostatic spindle. The structural form of the hydrostatic rotary table can be found, but is not limited to, the technical solution disclosed in patent application number 202021828430X, entitled "An Internal Feedback Precision Closed Hydrostatic Rotary Table." The structural form of the hydrostatic spindle can be found, but is not limited to, the technical solution disclosed in patent application number 2019108857129, entitled "A High-Precision Liquid Hydrostatic Spindle."

[0060] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A multifunctional composite vertical grinding machine with an added tail-end rotary support center structure, comprising a bed, a column, a rotary worktable mounted on the bed, and a spindle box with a grinding wheel mounted thereon; the spindle box is connected to the column via a horizontal and vertical composite drive guide mechanism, characterized in that: It also includes a tail end slewing support center structure; the slewing support center structure is vertically installed above the rotary worktable through a center support mechanism; when machining shaft parts, the slewing support center structure is aligned with the center of the rotary tooling table; The rotary table adopts a hydrostatic rotary table structure, the center structure adopts a hydrostatic center, and the grinding wheel is mounted on the spindle box via a hydrostatic spindle. The hydrostatic center includes a shaft frame and a center shaft inserted into the shaft frame. The shaft frame is connected to a center support mechanism. The center head of the center shaft extends from the lower end of the shaft frame, and the tail end of the center shaft extends from a tail end cap fixed to the tail end of the shaft frame. A pressure-bearing oil groove is formed on the outer ring surface of the center shaft inside the shaft frame. An oil inlet passage is formed on the center shaft, connecting each pressure-bearing oil groove with the tail end of the center shaft. A pressure-bearing oil cavity is formed between the pressure-bearing oil groove and the inner bore surface of the shaft frame, so that the center shaft is installed in the shaft frame by means of hydrostatic bearing support. An oil return hole for hydrostatic oil output is provided on the side wall of the shaft frame. A front oil seal structure is provided between the front end of the shaft bracket and the center shaft, and a tail oil seal structure is provided at the mating part of the tail end cover and the center shaft; an axial clamping mechanism is provided at the tail end of the center shaft to press the center head onto the workpiece. The pressure oil grooves set on the center shaft are one or more sets arranged symmetrically. Each pressure oil groove has a throttling zone with an oil inlet hole and connected to the oil inlet passage. The throttling zone of each pressure oil groove is connected to the part outside the throttling zone of another pressure oil groove in the same group through a feedback oil passage built into the center shaft. The feedback oil passage connects the two symmetrically arranged pressure oil grooves to form a static pressure circulation oil passage.

2. The multifunctional composite vertical grinding machine with an added tail-end rotary support center structure as described in claim 1, characterized in that: The vertical grinding machine is equipped with two spindle boxes, which are arranged left and right. One of the spindle boxes provides a mounting surface for the rotary support tip structure, which is mounted on the side wall of the spindle box through a tip support mechanism. The rotary support tip structure is linked with the horizontal and vertical composite drive guide mechanism of the spindle box.

3. The multifunctional composite vertical grinding machine with an added tail-end rotary support center structure as described in claim 1, characterized in that: The top support mechanism includes a top housing, a top bracket, and a top drive cylinder; the top housing is fixed above the column in a cantilevered manner, the rear end of the top bracket is connected to the front end of the top housing through a vertically arranged guide rail pair, and the top drive cylinder is fixedly installed on the top housing; the top structure is vertically installed on the top bracket and driven by the top drive cylinder.

4. The multifunctional composite vertical grinding machine with an added tail-end rotary support center structure as described in claim 1, characterized in that: The top support mechanism includes a small support column, a top bracket, and a top drive cylinder; the small support column is vertically fixedly installed on the bed, and the inner side of the small support column is connected to the top bracket through a vertically arranged guide rail pair; the top drive cylinder is fixedly installed on the upper part of the bed or the upper part of the small support column; the top structure is vertically installed on the top bracket and is driven by the top drive cylinder.

5. The multifunctional composite vertical grinding machine with an added tail-end rotary support center structure as described in claim 1, characterized in that: The top support mechanism is located on the side of the spindle box and includes a top support bracket and a second transverse and longitudinal composite drive guide mechanism. The top is vertically mounted on the top support bracket, and the top support bracket is connected to the column through the second transverse and longitudinal composite drive guide mechanism.

6. The multifunctional composite vertical grinding machine with an added tail-end rotary support center structure as described in claim 1, characterized in that: A piston chamber is provided at the tail end of the shaft bracket, and a piston head is provided at the tail end of the center shaft. The piston head and the piston chamber form a piston engagement. An oil hole is provided on the tail end or the side of the tail end of the shaft bracket. The oil hole communicates with the piston chamber, forming a hydraulic cylinder type axial clamping mechanism that acts on the center shaft.

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