CN202520799U - Controllable throttle device - Google Patents

Abstract

A controllable restrictor, including a restrictor seat, a throttle post and a spring, the restrictor seat is provided with a stepped central hole, the stepped central hole is composed of a large diameter hole, a middle diameter hole and a small diameter hole, the large diameter The hole is connected with the small diameter hole through the middle diameter hole. The throttle column is composed of a large diameter column, a medium diameter column and a small diameter column. The throttle column is installed in the restrictor seat. The large diameter column and the large diameter hole are closely matched. The top of the diameter column and the inner wall of the large diameter hole form a control oil chamber, and the oil inlet chamber is formed between the middle diameter column and the large diameter hole. A throttling gap communicating with the oil inlet chamber is formed between the diameter holes, and an oil collection chamber is formed between the small diameter column and the middle diameter hole, the small diameter column and the small diameter hole are closely matched, and the output channel connected with the oil collection chamber is opened on the small diameter column. The spring is arranged between the bottom end of the middle-diameter column and the bottom end of the middle-diameter hole. The controllable throttling device has a quick dynamic response to the change of the external load, realizes the active control of throttling parameters, and the control is convenient and accurate.

Description

Controllable throttle

technical field

The utility model relates to a throttling device for the spindle of a machine tool with hydrostatic pressure and dynamic and static pressure bearings in precision and ultra-precision machine tools, in particular to a controllable throttle.

Background technique

Precision and ultra-precision machining are indispensable means for the processing of aerospace optical components, key parts of national defense equipment and key parts of high-end civilian equipment. Precision and ultra-precision machining mainly depend on precision and ultra-precision machine tools. Due to the unique "error equalization effect", dynamic pressure effect and damping and vibration reduction effect of hydrostatic pressure and dynamic and static pressure bearing machine tool spindles, their rotation accuracy is much higher than that of rolling bearing spindles, and their carrying capacity is much higher than that of gas static pressure spindles. Therefore, it has been widely used in precision and ultra-precision machine tools.

Hydrostatic and dynamic and static pressure bearings can be divided into quantitative oil supply and constant pressure oil supply according to the oil supply method. Hydrostatic and hydrostatic bearings with quantitative oil supply are mainly used in the fields of spindles, workpiece shafts, turntables, guide rails, and lead screws of large heavy-duty machine tools. Many, the cost is also high. At present, in the field of precision ultra-precision machine tools with a large quantity and a wide range, hydrostatic and dynamic and static pressure bearings with constant pressure oil supply are generally used.

The hydrostatic and dynamic static pressure bearings that use constant pressure oil supply must be properly equipped and used with restrictors, so that the bearing capacity, rigidity and precision of the bearings can be effectively exerted. At present, the restrictors used in hydrostatic and dynamic static pressure bearings can be divided into two types: fixed restrictors and variable restrictors.

The existing fixed throttling methods include capillary throttling, small hole throttling, annular gap throttling (cylindrical surface, end face, conical surface) and surface throttling. Their common disadvantage is that when the pressure in the oil chamber increases, the oil entering the oil chamber decreases due to the decrease in the pressure difference before and after throttling, so the increase in the carrying capacity and stiffness is very limited.

In order to further improve the carrying capacity of hydrostatic and hydrostatic pressure bearings, domestic and foreign counterparts have adopted variable throttles. The existing variable throttle methods include film feedback throttling, slide valve feedback throttling and inner surface feedback throttling, etc. The disadvantages of film feedback throttling and spool valve feedback throttling are: (1) The restrictor has a large structural size and can only be placed outside the bearing body, so the feedback oil circuit is longer and the dynamic response to external load changes is relatively slow. Slow, which affects the improvement of dynamic stiffness; (2) The large size of the throttle increases the overall space occupied by the machine tool spindle; (3) The throttle is divided into two ways to supply oil to the two opposite oil chambers, The stiffness of the opposite oil chamber is affected by the parameters of the same restrictor at the same time. If the parameters are not selected properly, it is easy to cause the stiffness of the spindle system to be unstable, resulting in the spindle not working properly. The disadvantages of internal surface feedback throttling are: (1) It needs to occupy the area of the inner surface of the bearing oil chamber, resulting in a larger axial dimension of the bearing. For bearings with small inner hole sizes, inner surface throttling is difficult to process; (2) ) Due to the increase in the area of the inner surface, when the spindle rotates, the shear heat between the inner surface and the oil film increases, and the temperature rise of the bearing increases, which is not conducive to improving the high-speed performance of the spindle.

In addition, whether it is the above-mentioned fixed throttle or the variable throttle, there is a common deficiency, that is, once the throttle is selected, its throttling characteristics are determined, and cannot be adjusted and changed during the working process of the throttle. its throttling characteristics.

Due to the above-mentioned defects, the throttling method adopted by the existing hydrostatic pressure and dynamic and static pressure bearing machine tool spindles has not been fully applied on machine tools at present, and has not been able to realize mass production as a unit functional component.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art, provide a controllable throttling valve with simple and compact structure, rapid dynamic response to changes in external loads, active control of throttling parameters, and convenient and accurate control. streamer.

In order to solve the above technical problems, the utility model adopts the following technical solutions:

A controllable restrictor, including a restrictor seat, a throttle post and a spring, the restrictor seat is provided with a stepped central hole, and the stepped central hole is composed of a large-diameter hole, a middle-diameter hole and a small-diameter hole Composition, the large-diameter hole communicates with the small-diameter hole through the middle-diameter hole, the throttle column is a stepped column composed of large-diameter columns, medium-diameter columns and small-diameter columns, and the throttle column is installed on the node. In the flow device seat, the large-diameter column is closely matched with the large-diameter hole, the top of the large-diameter column and the inner wall of the large-diameter hole enclose a control oil chamber, and an oil inlet chamber is formed between the middle-diameter column and the large-diameter hole. An oil inlet channel communicating with the oil inlet chamber is opened on the throttle seat, a throttling gap communicating with the oil inlet chamber is formed between the middle diameter column and the middle diameter hole, and a throttling gap is formed between the small diameter column and the middle diameter hole An oil collection chamber is formed between the small diameter column and the small diameter hole. The small diameter column is provided with an output channel communicating with the oil collection chamber. The spring is arranged between the bottom end of the middle diameter column and the bottom end of the middle diameter hole. between. the

The oil inlet passage includes an annular oil supply groove and an oil inlet hole, the annular oil supply groove is arranged on the outer cylindrical surface of the restrictor seat, and the oil inlet hole communicates with the annular oil supply groove and the oil inlet chamber.

Threads are provided on the outer cylindrical surface of the restrictor seat.

Compared with the prior art, the utility model has the advantages of:

The controllable restrictor of the utility model has a short feedback oil circuit during self-adaptive adjustment, and has a quick dynamic response to changes in external loads, which is beneficial to improving the dynamic stiffness and increasing the stiffness and motion accuracy of the bearing. In addition, the controllable restrictor of the utility model can also adjust the axial position of the throttle column in the throttle seat by adjusting the oil pressure of the control oil circuit from the outside, and change the annular columnar throttle gap in its axial direction. The length in the direction, so as to change the throttling damping, to meet the stiffness needs to the maximum extent, this kind of controllable throttling device is more convenient and accurate to control throttling parameters, and the control response speed is fast, which is more conducive to increasing the stiffness and movement of the bearing precision. The structure of the controllable throttle of the utility model is simpler, more compact, and smaller than that of the film feedback throttle and the slide valve feedback throttle, and can be directly installed in the bearing body, which is beneficial to reducing the overall space occupied by the machine tool spindle, and the assembly process Good performance, convenient serialized standardized production, lower manufacturing cost, convenient maintenance and replacement; at the same time, because the structure of the controllable throttle is compact and small, it is possible to use a structure in which each bearing static pressure oil chamber is separately equipped with a controllable throttle, The precision of the self-adaptive adjustment for the pressure change in the static pressure oil chamber of the bearing is higher, and the problem caused by the self-adaptive adjustment of two opposing static pressure oil chambers of the bearing at the same time by using a restrictor in the prior art is avoided. The phenomenon that the stiffness of the spindle system is unstable. Compared with the internal surface feedback throttling structure, the controllable throttle of the utility model has a simpler structure and more convenient processing, and there is no phenomenon that the oil film is sheared and heated when the main shaft rotates, and the temperature rise of the bearing is low, which is beneficial Improve the high-speed performance of the spindle.

Description of drawings

Fig. 1 is a schematic diagram of the main sectional structure of the utility model.

Fig. 2 is an AA sectional view of Fig. 1 .

Fig. 3 is a structural schematic diagram of installing the utility model on a hydrostatic bearing.

FIG. 4 is a BB sectional view of FIG. 3 .

Each label in the figure means:

1. Throttle seat; 2. Throttle column; 3. Spring; 4. Control oil chamber; 5. Oil inlet chamber; 6. Throttle gap; 7. Oil collection chamber; 8. Output channel; 11. Large diameter Hole; 12, medium diameter hole; 13, small diameter hole; 14, oil inlet channel; 21, large diameter column; 22, medium diameter column; 23, small diameter column; 91, control oil circuit; 92, bearing oil supply oil circuit; 93, bearing static pressure oil cavity; 141, annular oil supply groove; 142, oil inlet hole.

Detailed ways

Fig. 1 and Fig. 2 have shown a kind of controllable restrictor embodiment of the utility model, and this controllable restrictor comprises restrictor seat 1, throttle post 2 and spring 3, and restrictor seat 1 is provided with The stepped center hole is composed of a large diameter hole 11, a middle diameter hole 12 and a small diameter hole 13. The large diameter hole 11 communicates with the small diameter hole 13 through the middle diameter hole 12. The throttling column 2 is formed by a large diameter column 21 , the middle-diameter column 22 and the small-diameter column 23 are connected to form a stepped column, the throttle column 2 is installed in the throttle seat 1, the large-diameter column 21 is closely matched with the large-diameter hole 11, and the top of the large-diameter column 21 and the large-diameter hole The inner wall of 11 encloses the control oil chamber 4, the oil inlet chamber 5 is formed between the middle diameter column 22 and the large diameter hole 11, the oil inlet passage 14 communicating with the oil inlet chamber 5 is opened on the restrictor seat 1, and the middle diameter column 22 A throttling gap 6 communicating with the oil inlet chamber 5 is formed between the middle diameter hole 12. The throttling gap 6 is in the shape of an annular column, and an oil collection chamber 7 is formed between the small diameter column 23 and the middle diameter hole 12. The oil collection chamber 7 and The throttling gap 6 is connected, and the small-diameter column 23 is closely matched with the small-diameter hole 13. The small-diameter column 23 is provided with an output channel 8 communicating with the oil collection chamber 7. The output channel 8 is connected by two radial holes and an axial hole. As a result, the spring 3 is abutted between the bottom end of the middle-diameter column 22 and the bottom end of the middle-diameter hole 12 , and the spring 3 is used to assist the throttle post 2 to return to one end of the large-diameter column 21 . The oil inlet channel 14 includes an annular oil supply groove 141 and an oil inlet hole 142 . Threads are provided on the outer cylindrical surface of the restrictor seat 1 to facilitate the connection and installation of the restrictor seat 1 .

The working principle of the controllable restrictor of the present invention will be further explained below in conjunction with the hydrostatic bearing of the main shaft in the ultra-precision machine tool:

As shown in Figures 3 and 4, the controllable throttle device of the present invention is installed into the hydrostatic bearing of the main shaft in the ultra-precision machine tool, so that the control oil chamber 4 is connected with the independent control oil circuit 91, so that the annular oil supply groove 141 is connected with the bearing oil supply oil passage 92 of the hydrostatic bearing, so that the output channel 8 is connected with the bearing static pressure oil chamber 93 . The control oil circuit 91 supplies oil to the control oil chamber 4, and the bearing oil supply circuit 92 supplies oil to the static pressure oil chamber 93 of the bearing. , quickly enter the oil inlet chamber 5, and then enter the oil collection chamber 7 after throttling through the throttle gap 6, and the throttled pressure oil is gathered in the oil collection chamber 7 and then enters the bearing through the output channel 8 on the small diameter column 23 Hydrostatic oil chamber 93. The controllable restrictor of the utility model can carry out self-adaptive adjustment according to the pressure change in the static pressure oil chamber 93 of the bearing. move, the length of the annular columnar throttling gap 6 in the axial direction decreases, and the throttling liquid resistance decreases, so that the liquid entering the bearing static pressure oil chamber 93 further increases; when the pressure of the bearing static pressure oil chamber 93 decreases , the throttling column 2 moves to one end of the small-diameter column 23, the length of the annular columnar throttling gap 6 in the axial direction increases, and the throttling liquid resistance increases, so that the liquid entering the static pressure oil chamber 93 of the bearing is further reduced, thus It can be seen that the controllable restrictor of the utility model has a short feedback oil circuit during self-adaptive adjustment, and has a quick dynamic response to changes in external loads, which is conducive to improving the dynamic stiffness and increasing the stiffness and motion accuracy of the bearing. In addition, the controllable throttle of the present invention can also adjust the axial position of the throttle column 2 in the throttle seat 1 by adjusting the oil pressure of the control oil chamber 4 from the outside, and change the annular columnar throttle gap 6 The length in the axial direction can change the throttling damping to meet the rigidity requirements to the greatest extent. This kind of controllable throttling device is more convenient and accurate in controlling the throttling parameters, and the control response speed is fast, which is more conducive to adding bearings. stiffness and motion precision. The structure of the controllable throttle of the utility model is simpler, more compact, and smaller than that of the film feedback throttle and the slide valve feedback throttle, and can be directly installed in the bearing body, which is beneficial to reducing the overall space occupied by the machine tool spindle, and the assembly process Good performance, convenient serialized standardized production, lower manufacturing cost, convenient maintenance and replacement; at the same time, because the structure of the controllable throttle is compact and small, it is possible to use a structure in which each bearing static pressure oil chamber 93 is separately equipped with a controllable throttle , so that the precision of the self-adaptive adjustment to the pressure change in the bearing static pressure oil chamber 93 is higher, avoiding the self-adaptation of two opposing bearing static pressure oil chambers 93 at the same time by using a restrictor in the prior art The phenomenon that the stiffness of the spindle system caused by adjustment is unstable. Compared with the internal surface feedback throttling structure, the controllable throttle of the utility model has a simpler structure and more convenient processing, and there is no phenomenon that the oil film is sheared and heated when the main shaft rotates, and the temperature rise of the bearing is low, which is beneficial Improve the high-speed performance of the spindle.

The above are only preferred embodiments of the utility model, and do not limit the utility model in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the scope of the technical solution of the present utility model, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the utility model, or modify it into an equivalent change, etc. effective example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical proposal of the present invention.

Claims (3)

1. A controllable choke, characterized in that it includes a choke seat (1), a choke post (2) and a spring (3), and the choke seat (1) is provided with a stepped center hole , the stepped central hole is composed of a large diameter hole (11), a middle diameter hole (12) and a small diameter hole (13), and the large diameter hole (11) passes through the middle diameter hole (12) and the small diameter hole (13) connected, the throttling column (2) is in the shape of a stepped column composed of a large-diameter column (21), a medium-diameter column (22) and a small-diameter column (23), and the throttle column (2) is installed on the In the restrictor seat (1), the large-diameter column (21) is closely matched with the large-diameter hole (11), and the top of the large-diameter column (21) and the inner wall of the large-diameter hole (11) enclose a control oil chamber ( 4), the oil inlet cavity (5) is formed between the middle diameter column (22) and the large diameter hole (11), and the throttle seat (1) is provided with an inlet connected to the oil inlet cavity (5). The oil channel (14), the throttling gap (6) communicating with the oil inlet chamber (5) is formed between the middle diameter column (22) and the middle diameter hole (12), the small diameter column (23) and the middle diameter An oil collection chamber (7) is formed between the holes (12), and the small diameter column (23) is closely matched with the small diameter hole (13). The channel (8), the spring (3) is arranged between the bottom end of the middle-diameter column (22) and the bottom end of the middle-diameter hole (12). 2. The controllable throttle according to claim 1, characterized in that: the oil inlet channel (14) includes an annular oil supply groove (141) and an oil inlet hole (142), and the annular oil supply groove (141) Located on the outer cylindrical surface of the throttle seat (1), the oil inlet hole (142) communicates with the annular oil supply groove (141) and the oil inlet chamber (5). 3. The controllable restrictor according to claim 1 or 2, characterized in that: the outer cylindrical surface of the restrictor seat (1) is provided with threads.

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