Large gantry honing machine tool

Abstract

According to the large gantry honing machine tool, the two reciprocating oil cylinders are arranged on the two opposite inner walls of the frame structure, the two sensors are arranged on the oil supply loops of the two reciprocating oil cylinders, when the honing head moves to the positions with different inner diameters, the reciprocating oil cylinders need to apply larger thrust to the main shaft rotating mechanism, and therefore the honing head rotates; therefore, resistance borne by the honing head when an inner hole becomes smaller is overcome, pressure data collected by the sensor becomes larger, then the control system controls the reciprocating oil cylinder to change the honing range, full-stroke honing is changed into repeated honing in the range, and after the data of the pressure sensor is within an original preset range error, the honing is changed into full-stroke honing. Therefore, the problem of low honing precision caused by deflection of the axis of the honing head due to inconsistent inner diameters of the workpieces is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of large gantry honing machines and relates to a large gantry honing machine tool. Background Art

[0002] Large vertical precision CNC honing machines are primarily used for honing large-scale holes in precision parts, such as housings, cylinder liners, and hydraulic cylinders. Their key technical characteristics are large parts, resulting in very large maximum honing diameters and lengths. Furthermore, they require high machining precision, which in turn demands high machine motion drive force and high control accuracy. The honing solutions used on small and medium-sized honing machines are not applicable to these machines.

[0003] In the prior art, the torque generated by the honing head during operation is reduced by aligning the honing head axis with the frame, thereby alleviating the problem of low honing accuracy caused by the deflection of the honing head axis.

[0004] However, in actual application, due to the different inner diameters of the workpiece, when the honing head moves to the inconsistent part of the workpiece inner hole, the axis of the honing head will still be deflected. At the same time, the honing head will exert excessive pressure on the hard point, causing damage to the honing head, thereby leading to low honing accuracy.

[0005] At the same time, since the large vertical honing machine needs to adjust the workpiece to a suitable position in the early stage of processing and use a fixture to position it before processing can be carried out, the workpiece positioning device of the large vertical honing machine in the existing technology requires manual adjustment of the position of the workpiece, so it is difficult to achieve accurate positioning, which leads to the problem of low honing accuracy. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem in the prior art that a large vertical honing machine has low honing precision when actually processing large-sized workpieces.

[0007] In order to achieve the above-mentioned purpose, the present application proposes a large gantry honing machine tool, comprising: a spindle rotation mechanism; a connecting rod mechanism connected to the output end of the spindle rotation mechanism and a large-aperture honing head arranged at the output end of the connecting rod mechanism; a frame structure for fixing the spindle rotation mechanism; also including: a driving mechanism arranged on the inner wall of the frame structure and connected to both sides of the spindle rotation mechanism; a positioning device arranged at the bottom of the inner side of the frame structure; wherein the driving mechanism includes: two reciprocating cylinders separated on the two inner walls opposite to each other from the bottom of the frame structure to 1 / 2 of the height; a linear rail arranged on the two inner walls opposite to each other from the top of the frame structure to 1 / 2 of the height and two first pressure sensors arranged on the oil supply circuit of the reciprocating cylinder.

[0008] In the present application, the driving mechanism arranged on the inner walls on both sides of the frame is used to drive the spindle rotation mechanism, the connecting rod mechanism and the large-aperture honing head to move in the vertical direction to realize the honing of the inner hole of the workpiece. Among them, the two reciprocating cylinders can make the two sides of the spindle rotation mechanism move synchronously. At the same time, the two first pressure sensors arranged on the reciprocating cylinder oil supply circuit are used to detect the pressures respectively exerted on the oil delivery circuit and the oil inlet circuit.

[0009] Furthermore, in order to realize the connection between the linear rail and the spindle rotation mechanism, two linear rails are symmetrically arranged on the inner wall of either side of the frame structure; at the same time, two mutually perpendicular hinges are provided on the two linear rails to respectively connect the adjacent two side walls of the spindle rotation mechanism. Thus, a total of four hinges cover the four side walls of the spindle rotation mechanism.

[0010] Furthermore, in order to achieve positioning of the workpiece along the width direction of the frame structure, the positioning device includes: a servo movable slide arranged at the bottom of the frame structure.

[0011] Furthermore, in order to achieve preliminary positioning of the workpiece in the vertical direction, the positioning device also includes: an assembled fixture arranged on the top of the servo moving slide; wherein, the assembled fixture includes: an elevation frame directly connected to the top of the servo moving slide, the elevation frame is set to be single or stacked into multiple according to the actual processing height of the workpiece; and a positioning platform arranged on the top of the elevation frame.

[0012] Furthermore, in order to prevent the honing head from undergoing plastic deformation and affecting the honing accuracy when encountering hard points or inner holes of workpieces with different shapes, the large gantry honing machine also includes: a pressure-maintaining and release feed module; the pressure-maintaining and release feed module includes: a hydraulic system; a second pressure sensor connected to the output end of the hydraulic system and arranged between the expansion mechanism of the large-aperture honing head and the push rod; a control module integrated in the hydraulic system; a hydraulic control valve and a pressure-maintaining module arranged on the output circuit of the hydraulic system.

[0013] Furthermore, the control module on the hydraulic system adopts a PID control algorithm.

[0014] Furthermore, in order to achieve diversity in pressure-maintaining methods, the pressure-maintaining module adopts either hydraulic pressure-maintaining or mechanical pressure-maintaining.

[0015] The beneficial effects of this application are: 1. A large gantry honing machine tool of the present application is provided with two reciprocating cylinders on two opposite inner walls of a frame structure, and two sensors are provided on the oil supply circuits of the two reciprocating cylinders. When the honing head moves to a position where the inner diameter of the workpiece is inconsistent or a hard point appears, the reciprocating cylinder needs to apply a greater thrust to the spindle rotation mechanism to overcome the resistance encountered by the honing head when the inner hole becomes smaller and hard points appear. At this time, after the pressure data collected by the sensor increases and reaches a preset value, the data is transmitted to the control system to adjust the honing range of the reciprocating cylinder, from full-stroke honing to repeated honing in the area, until the pressure sensor data is within the originally preset range error, and then it is changed to full-stroke honing, thereby overcoming the problem of the honing head axis being deflected due to the inconsistent inner diameter of the workpiece, which in turn leads to low honing accuracy.

[0016] 2. The honing mechanism of the present application is driven by two symmetrically arranged reciprocating cylinders. This dual-power synchronous drive mode has stronger stability in the application scenario of large-scale vertical honing, and can timely predict and correct the situation when the connecting rod mechanism deflects.

[0017] 3. The pressure-maintaining and releasing feeding technology of the present application can cope with the complex environment of uneven inner holes of the workpiece. When the radial length of one or more local points becomes smaller, the honing head assembly in the existing technology will continue to apply pressure to the inner hole of the workpiece. However, when the pressure at this point is released too much and the pressure applied by the honing head assembly is too large, the rod inside the honing head assembly will undergo plastic deformation, causing damage to the honing head and scrapping of the workpiece. The pressure-maintaining and releasing feeding technology of the present application can automatically reduce the feed speed of the feeding system to maintain constant pressure when the processing resistance increases (for example, encountering hard points or changes in the shape of the workpiece), thereby protecting the honing head while repeatedly honing the uneven parts of the inner hole of the workpiece, thereby improving the honing accuracy at the hard points. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the structure of a large gantry honing machine tool in an embodiment of the present application; Figure 2 This is a side view of a large gantry honing machine tool in an embodiment of the present application; Figure 3 This is a schematic diagram of the assembly position of the hinge and the main shaft rotation mechanism in the embodiment of the present application; Figure 4This is a schematic diagram of the position of the first pressure sensor in the embodiment of the present application; Figure 5 This is a control logic diagram of the pressure-maintaining and releasing feeding module in the embodiment of the present application; Description of reference numerals: 1. Spindle rotation mechanism; 2. Connecting rod mechanism; 3. Large aperture honing head; 4. Frame structure; 41. Bed; 42. Lower column; 43. Upper column; 44. Crossbeam; 45. Upper cover; 5. Driving mechanism; 51. Reciprocating cylinder; 52. Linear rail; 53. First pressure sensor; 54. Hinge; 6. Positioning device; 61. Servo movable slide; 62. Assembled fixture; 621. Elevating frame; 622. Positioning platform; 7. Pressure-maintaining and releasing feeding module; 71. Hydraulic system; 72. Control module; 73. Hydraulic control valve; 74. Pressure-maintaining module. DETAILED DESCRIPTION

[0020] The following will be combined with the Figures 1 to 5 The embodiments of the technical solution of the present application are described in detail. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application. In addition, the technical features involved in the various embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

[0021] Example 1: like Figures 1 to 5 The diagram shows a large gantry honing machine tool of the present application, wherein the frame structure 4 includes: a bed arranged on the ground, a lower column and an upper column arranged on the bed, wherein a crossbeam is provided at the junction of the upper column and the lower column, and an upper cover is provided on the top of the upper column. Thus, the upper cover, the upper column, the lower column, and the bed form a rectangular frame structure, and the crossbeam divides the rectangular structure into two parts, the upper and lower parts.

[0022] Please refer to Figures 1 to 4In order to overcome the problem of low honing accuracy caused by inconsistent workpiece inner diameters, a large gantry honing machine tool of the present application is provided with two reciprocating cylinders 51 on the two opposite inner walls of the frame structure 4. These two reciprocating cylinders 51 are used to drive the spindle rotation mechanism 1, the connecting rod mechanism 2, and the large-aperture honing head 3 to move in the vertical direction, thereby achieving the honing of the inner hole of the workpiece. When the honing head 3 moves to a position with inconsistent inner diameters, the resistance to the honing head 3 increases due to the smaller inner hole. At this time, the reciprocating cylinder 51 needs to apply a greater thrust to the spindle rotation mechanism 1 to overcome this resistance. Two first pressure sensors 53 are respectively provided on the oil supply circuits of the two reciprocating cylinders 51 for real-time detection of the pressure on the reciprocating cylinders 51.

[0023] Further, please refer to Figure 4 and Figure 5 , Figure 4 The diagram illustrates the specific installation locations of the first pressure sensors 53 in the oil supply circuit. When the honing head 3 encounters a point where the inner diameter decreases, the pressure data collected by the two first pressure sensors 53 increases and exceeds a preset range. Specifically, when the large-aperture honing head 3 hones a workpiece from top to bottom, as the workpiece inner diameter decreases, the reciprocating cylinder 51 requires greater thrust. The pressure change at the oil inlet most directly reflects this demand. The first pressure sensors 53 in the oil supply circuit detect this pressure change. The first pressure sensor 53 installed at the oil return port also detects this pressure change and assists in determining whether the cylinder is operating properly. When the two first pressure sensors 53 detect that the hydraulic oil pressure in the cylinder exceeds the preset range, they transmit a signal to the control module 72. Based on this pressure data, the control system controls the reciprocating cylinder 51 to change the honing range, from full-stroke honing to repeated honing within the increased resistance range. This is done until the data from the two first pressure sensors 53 return to within the preset range error, at which point full-stroke honing is resumed. In this way, the machine tool can automatically adapt to the inconsistency of the workpiece inner diameter, avoiding the deflection of the honing head axis and thus improving the honing accuracy.

[0024] As a preferred solution, when the honing head 3 moves to the position where hard points appear on the inner wall of the workpiece, the resistance encountered by the honing head 3 suddenly increases. Since the positions of the hard points are generally not evenly distributed along the inner hole wall of the workpiece, but appear randomly, the resistance encountered by the honing head 3 at this time will destroy the original balance state of the honing head 3, thereby causing the thrust provided by the two reciprocating cylinders 51 on both sides to deviate, thereby causing the pressure data collected by the two first pressure sensors 53 to fluctuate. When the fluctuation exceeds the preset range, the first pressure sensor 53 will send a signal to the control module 72. The control system controls the reciprocating cylinder 51 to change the honing range based on these pressure data, from full-stroke honing to repeated honing within the resistance fluctuation range.

[0025] Example 2: like Figures 1 to 5 The diagram shows a large gantry honing machine tool of the present application. In order to improve stability through dual-power synchronous drive, the honing mechanism of the present application is driven by two symmetrically arranged reciprocating cylinders 51. This dual-power synchronous drive method shows stronger stability in the application scenario of large vertical honing. The two reciprocating cylinders 51 are respectively located on both sides of the main shaft rotation mechanism 1, and can synchronously provide sufficient thrust to ensure the stability of the main shaft rotation mechanism 1, the connecting rod mechanism 2 and the large-aperture honing head 3 during movement. In addition, since two first pressure sensors 53 are provided, when the connecting rod mechanism 2 deflects, the pressure data collected by the two sensors will differ. The control system can timely predict and correct the deflection based on these difference data, thereby further improving the stability and accuracy of honing.

[0026] Example 3: like Figures 1 to 5 The diagram illustrates a large gantry honing machine of the present application. To improve the honing accuracy of hard-points using a pressure-release feed technology, the large gantry honing machine of the present application also includes a pressure-release feed module 7, which comprises a hydraulic system 71, a control module 72, a hydraulic control valve 73, and a pressure-maintaining module 74. During machining, when the honing head 3 encounters a hard point or the workpiece shape changes, causing increased machining resistance, the first pressure sensor 53 detects the pressure change and transmits a signal to the control module 72. The control module 72 utilizes a PID control algorithm, a commonly used control algorithm that can quickly and accurately adjust the flow of oil in and out of the hydraulic system 71 based on pressure deviations. It automatically adjusts the opening of the hydraulic control valve 73 within a preset pressure range to reduce the feed speed of the piston rod of the reciprocating cylinder 51 while maintaining constant pressure. This in turn controls the feed rate of the honing head's ejector relative to the expansion mechanism, preventing the ejector from continuously applying pressure to the expansion mechanism when encountering a hard point, thereby achieving a stable pressure-maintaining effect.

[0027] At the same time, the pressure maintaining module 74 adopts either hydraulic pressure maintaining or mechanical pressure maintaining to ensure repeated honing under constant pressure. This method can protect the honing head 3 from plastic deformation and improve the honing accuracy at the hard points.

[0028] Furthermore, hydraulic pressure maintenance can be achieved by installing corresponding pressure-maintaining circuits at the oil inlet and outlet of the hydraulic cylinder. Mechanical pressure maintenance can be achieved by adding springs to the honing head's push rod and expansion mechanism. The spring's preload provides expansion force, and the spring's elastic deformation adapts to pressure changes. The above-mentioned hydraulic and mechanical pressure maintenance are prior art and will not be elaborated here.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A large gantry honing machine tool, comprising: Spindle rotation mechanism (1); A connecting rod mechanism (2) connected to the output end of the spindle rotation mechanism (1); a large-aperture honing head (3) arranged at the output end of the connecting rod mechanism (2) and a frame structure (4) for limiting the spindle rotation mechanism (1); characterized in that it also includes: a driving mechanism (5) arranged on the inner wall of the frame structure (4) and connected to both sides of the spindle rotation mechanism (1); a positioning device (6) arranged at the bottom of the inner side of the frame structure (4); the driving mechanism (5) includes: two reciprocating cylinders (51) separated on two inner walls relative to each other at a height of 1 / 2 from the bottom of the frame structure (4); a linear rail (52) arranged on two inner walls relative to each other at a height of 1 / 2 from the top of the frame structure (4) and two first pressure sensors (53) arranged on the oil supply circuit of the reciprocating cylinder (51).

2. A large gantry honing machine according to claim 1, characterized in that: The frame structure (4) comprises: a bed (41) arranged on the ground, a lower column (42) and an upper column (43) arranged on the bed (41), wherein a crossbeam (44) is provided at the junction of the upper column (42) and the lower column (43), and an upper cover (45) is provided on the top of the upper column (43), thereby forming a rectangular frame structure with the upper cover (45), the upper column (43), the lower column (42), and the bed (41).

3. The large gantry honing machine according to claim 1, characterized in that: Two linear rails (52) are symmetrically arranged on the inner wall of either side of the frame structure (4); at the same time, two mutually perpendicular hinges (54) are provided on the two linear rails (52) to respectively connect the adjacent two side walls of the main shaft rotation mechanism (1), thereby a total of four hinges (54) cover the four side walls of the main shaft rotation mechanism (1).

4. A large gantry honing machine according to claim 1, characterized in that: The positioning device (6) comprises: a servo movable slide (61) arranged at the bottom of the frame structure (4).

5. A large gantry honing machine according to claim 4, characterized in that: The positioning device (6) further includes: the assembled fixture (62) arranged on the top of the servo movable slide (61); wherein the assembled fixture (62) includes: an elevation frame (621) directly connected to the top of the servo movable slide (61), the elevation frame (621) being arranged as a single frame or stacked as multiple frames according to the actual processing height of the workpiece; and a positioning platform (622) arranged on the top of the elevation frame (621).

6. The large gantry honing machine according to claim 1, characterized in that: The large gantry honing machine tool further comprises: a pressure-maintaining and releasing feeding module (7); the pressure-maintaining and releasing feeding module (7) comprises: a hydraulic system (71); a second pressure sensor (72) connected to an output end of the hydraulic system (71) and arranged between the expansion mechanism of the large-aperture honing head (3) and the ejector rod; a control module (73) integrated on the hydraulic system (71); a hydraulic control valve (74) and a pressure-maintaining module (75) arranged on an output circuit of the hydraulic system (71).

7. A large gantry honing machine according to claim 6, characterized in that: The control module (73) adopts a PID control algorithm.

8. The large gantry honing machine according to claim 6, characterized in that: The pressure maintaining module (75) adopts either hydraulic pressure maintaining or mechanical pressure maintaining.

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