阅读说明：本技术 滚珠螺杆 (Ball screw ) 是由 蔡政祐 庄裕纬 魏照恩 于 2019-08-20 设计创作，主要内容包括：本发明提供一种滚珠螺杆,适于侦测一冷却液,包括一螺杆、一螺母、复数个密封件、一感测器、一信号处理单元以及一盖板。螺母包括一本体以及一端面,本体上设置有一贯孔以及一流道,螺母通过贯孔螺设于螺杆上,端面上设置有复数个开口,且这复数个开口连通于流道。这复数个密封件配置于这复数个开口内。感测器配置于这复数个密封件的其中之一密封件上用以感测冷却液的一压力,并输出一原始信号。信号处理单元电性连接于感测器,用以接收原始信号,并将原始信号转换为一数字信号。盖板配置于感测器上且固设于螺母。(The invention provides a ball screw suitable for detecting a cooling liquid, which comprises a screw, a nut, a plurality of sealing pieces, a sensor, a signal processing unit and a cover plate. The nut comprises a body and an end face, wherein the body is provided with a through hole and a flow passage, the nut is screwed on the screw rod through the through hole, the end face is provided with a plurality of openings, and the plurality of openings are communicated with the flow passage. The plurality of sealing members are disposed in the plurality of openings. The sensor is arranged on one of the plurality of sealing elements for sensing the pressure of the cooling liquid and outputting a raw signal. The signal processing unit is electrically connected to the sensor and used for receiving the original signal and converting the original signal into a digital signal. The cover plate is arranged on the sensor and is fixedly arranged on the nut.)

1. A ball screw adapted to sense a cooling fluid, the ball screw comprising:

a screw;

the nut comprises a body and an end face, wherein the body is provided with a through hole and a flow passage, the nut is screwed on the screw rod through the through hole, the end face is provided with a plurality of openings, and the openings are communicated with the flow passage;

a plurality of sealing members disposed in the plurality of openings;

a sensor, disposed on one of the plurality of sealing members for sensing a pressure of the cooling liquid and outputting an original signal;

a signal processing unit electrically connected to the sensor, the signal processing unit being used for receiving the original signal and converting the original signal into a digital signal; and

and the cover plate is arranged on the sensor and is fixedly arranged on the nut.

2. The ball screw of claim 1, wherein: the one of the sealing members further includes a protrusion, and the sensor is disposed on the protrusion.

3. The ball screw of claim 2, wherein: the orthographic projection area of the convex part on the cover plate is 60% to 70% of the orthographic projection area of the sensor on the cover plate.

4. The ball screw of claim 1, wherein: the digital signal processing device also comprises a control unit and a memory unit, wherein the sensor, the signal processing unit, the control unit and the memory unit are electrically connected with each other, the signal processing unit outputs the digital signal to the control unit, and the memory unit stores the digital signal.

5. The ball screw of claim 4, wherein: the digital signal processing device comprises a control unit, a digital signal processing unit and a prompting unit, wherein the control unit is used for controlling the digital signal processing unit to output a preset signal, the prompting unit is electrically connected with the control unit and outputs a first prompting signal when an error amount of the digital signal and the preset signal is within a +/-20% threshold of the preset signal, the prompting unit outputs a second prompting signal when the error amount is within a 20% to 40% threshold or a-20% to-40% threshold of the preset signal, and the prompting unit outputs a third prompting signal when the error amount exceeds the +/-40% threshold of the preset signal.

6. The ball screw of claim 1, wherein: the sensor is a piezoresistive sensor.

7. The ball screw of claim 1, wherein: the plurality of sealing elements are symmetrically arranged along the circumferential direction of the nut, and one surface of the cover plate is coplanar with the end surface.

Technical Field

The present invention relates to a ball screw, and more particularly, to a ball screw capable of detecting a flow rate or a pressure of a coolant by means of a sensor disposed on a sealing member.

Background

A screw is a mechanism device quite common in the industrial field. Generally, when the screw and the nut disposed on the screw are operated, a large amount of heat is easily generated due to the relative movement therebetween, and therefore, an operator often pours a lubricating fluid into the screw in advance to reduce the frictional resistance between the members, or provides a flow passage inside the nut to continuously remove the heat by the flow of the cooling fluid. However, if the flow rate of the cooling fluid is insufficient, the generated heat cannot be smoothly taken away, and the temperature of the components is in danger of continuously rising, and if the flow rate of the cooling fluid is too high, the cooling fluid can explode and spread to other components which need to be kept dry. Therefore, it is an important issue to check the instantaneous flow rate of the coolant.

In order to solve the above problems, there is a design of disposing a sensor inside a nut in the prior art, for example, taiwan patent publication No. TWI572797 discloses a double-nut ball screw in which an annular force sensor is disposed at the bottom end of an annular deformable platform to sense pre-pressure, and the pressure of fluid can be sensed by pressing the opposite surfaces of two nuts. However, both the annular deformable platform and the annular force sensor are difficult to process, and thus the manufacturing cost is increased.

Disclosure of Invention

The present invention provides a ball screw, which can detect the flow rate or pressure of cooling liquid in real time by means of a sensor arranged on a sealing element, and the sensor does not need to be processed in a complex way, so that the industrial cost can be saved.

The ball screw of the invention is suitable for detecting a cooling liquid and comprises a screw, a nut, a plurality of sealing elements, a sensor, a signal processing unit and a cover plate. The nut comprises a body and an end face, wherein the body is provided with a through hole and a flow passage, the nut is screwed on the screw rod through the through hole, the end face is provided with a plurality of openings, and the plurality of openings are communicated with the flow passage. The plurality of sealing members are disposed in the plurality of openings. The sensor is arranged on one of the plurality of sealing elements for sensing the pressure of the cooling liquid and outputting a raw signal. The signal processing unit is electrically connected to the sensor and used for receiving the original signal and converting the original signal into a digital signal. The cover plate is arranged on the sensor and is fixedly arranged on the nut.

Preferably, one of the sealing members further includes a protrusion, and the sensor is disposed on the protrusion. Thus, the pressure of the cooling liquid fed back to the sealing member can be more effectively transmitted to the sensor.

Preferably, the orthographic projection area of the convex part on the cover plate is 60% to 70% of the orthographic projection area of the sensor on the cover plate. Therefore, the effective sensing area of the sensor can be best met, and the sensitivity and the accuracy of the sensing are improved.

Preferably, the ball screw further comprises a control unit and a memory unit, wherein the sensor, the signal processing unit, the control unit and the memory unit are electrically connected to each other, the signal unit outputs a digital signal to the control unit, and the memory unit stores the digital signal so as to more completely track the pressure or the flow rate of the cooling liquid.

Preferably, the ball screw further comprises a prompt unit electrically connected to the control unit, the prompt unit outputs a first prompt signal when an error amount between the digital signal and a predetermined signal is within a ± 20% threshold of the predetermined signal, the prompt unit outputs a second prompt signal when the error amount is within a 20% to 40% threshold or a-20% to-40% threshold of the predetermined signal, and the prompt unit outputs a third prompt signal when the error amount exceeds the ± 40% threshold of the predetermined signal. Therefore, the current flow state of the cooling liquid can be prompted to a user in real time.

Preferably, the sensor is a piezoresistive sensor for receiving pressure from the sealing member and generating a corresponding resistance signal.

Preferably, the plurality of sealing elements are symmetrically arranged along a circumference of the nut, and a surface of the cover plate is coplanar with the end surface.

Therefore, the flatness of the overall appearance of the invention can be improved, and the invention is not easy to collide or interfere with other components.

Drawings

FIG. 1 is a perspective view of a ball screw according to an embodiment of the present invention;

FIG. 2 is a partial exploded view of the ball screw of FIG. 1;

FIG. 3 is a perspective view of the seal of FIG. 2;

FIG. 4 is a side view of the seal of FIG. 3;

FIG. 5 is a cross-sectional view of the ball screw of FIG. 2 taken along section A-A;

FIG. 6 is an enlarged view of a portion of area B of FIG. 5;

FIG. 7 is a block diagram of the electrical components of the ball screw of FIG. 1;

FIG. 8 is a flowchart illustrating a step of detecting the cooling fluid by the ball screw of FIG. 7.

Description of reference numerals: 10-ball screw; 100-screw rod; 200-a nut; 210-a body; 220-end face; 300-a seal; 310-a convex part; 320-a cover part; 330-a connecting part; 340-a seal; 350-gasket; 400-a sensor; 500-cover plate; 510-a surface; 600-a signal processing unit; 700-a control unit; 800-a memory cell; 900-a prompt unit; a C-flow channel; h-through hole; an O-opening; r-gap; w-wall surface.

Detailed Description

The foregoing and other technical and other features and advantages of the invention will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. The following examples refer to directional terms such as: up, down, left, right, front or rear, etc., are referred to only in the direction of the attached drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1 is a schematic perspective view of a ball screw according to an embodiment of the present invention, and fig. 2 is an exploded view of a part of the ball screw of fig. 1, please refer to fig. 1 and fig. 2. The ball screw 10 of the present embodiment includes a screw 100, a nut 200, a plurality of sealing members 300, a sensor 400, and a cover plate 500. The nut comprises a body 210 and an end face 220, wherein the body 210 is provided with a through hole H and a flow passage, the end face 220 is provided with a plurality of openings O, the openings O are communicated with the flow passage, and the sealing elements 300 are arranged in the openings O; the sensor 400 is disposed on one of the plurality of sealing members 300, and the cap plate 500 is disposed on the sensor 400 and is fixedly secured to the nut 200.

In detail, the nut 200 is screwed on the screw 100 through the through hole H, wherein the inner side of the through hole H is provided with a thread, so that the nut 200 can move relative to the screw 100 through the thread on the inner side of the through hole H. Since the two components generate high heat during the relative movement, the cooling liquid is disposed in the flow passage of the nut 200 to reduce the temperature of the nut 200. Since the openings O communicate with the flow channels and the plurality of sealing members 300 are disposed in the plurality of openings O, the pressure generated by the cooling liquid is directly fed back to the sealing members 300. As shown in fig. 2, the shape of the sealing member 300 corresponds to the opening O, and in order to prevent the sealing member 300 from sealing incompletely to cause leakage of the cooling fluid, the sealing member 300 is further provided with a gasket 350 so as to be more closely coupled to the opening O. After the sealing members 300 are configured, in order to detect the flow rate of the cooling fluid, a sensor 400 is configured on one sealing member 300 of the plurality of sealing members 300 to sense the pressure of the cooling fluid fed back to the sealing member 300. After the sensor 400 is configured, the cover plate 500 is configured on the sensor 400, and the cover plate 500 is fixed to the nut 200 by screws or other fasteners.

It should be noted that, as shown in fig. 2, the plurality of sealing members 300 of the present embodiment are symmetrically arranged along the circumferential direction of the nut 200, and such an arrangement can reduce pressure variation of the cooling fluid due to the difference of the sealing degree at different positions.

Fig. 3 is a perspective view of the sealing member of fig. 2, and fig. 4 is a side view of the sealing member of fig. 3, please refer to fig. 3 and fig. 4. In the present embodiment, each of the plurality of sealing members 300 has a cover 320, a connecting portion 330 and a sealing portion 340, wherein the connecting portion 330 connects the cover 320 and the sealing portion 340, and the sealing members 300 are disposed in the opening O with the sealing portion 340 facing the opening O. When the sealing member 300 is disposed inside the opening O, the gasket 350 is disposed between the cover 320 and the sealing portion 340, and therefore, the size of the connecting portion 330 is designed to be slightly smaller than that of the cover 320 and the sealing portion 340, so that the gasket 350 is not separated from the sealing member 300 by sliding up and down when being sleeved on the connecting portion 330 between the cover 320 and the sealing portion 340. In other words, when the sealing member 300 is completely configured, an orthographic area of the connection part 330 on the cap plate 500 is smaller than an orthographic area of the cap part 320 and the sealing part 340 on the cap plate 500.

It is worth mentioning that the outer annular surface of the sealing portion 340 is designed as a tapered surface as shown in fig. 4, such that the sealing member 300 can be more closely attached to the wall surface of the opening O to achieve a better leakage-proof effect when the flow rate of the cooling fluid is increased, and the details will be described later.

In the present embodiment, the sensor 400 is a piezoresistive sensor capable of receiving a pressure from the sealing member 300 to generate a corresponding resistance signal. In order to enable the pressure of the cooling liquid fed back to the sealing member 300 to be more effectively transmitted to the sensor 400, in the present embodiment, the sealing member 300 configuring the sensor 400 further includes a protrusion 310, and the sensor 400 is configured on the protrusion 310. As a result of experimental tests, when the size of the protrusion 310 is designed to be 60% to 70% of the sensor 400, the effective sensing area of the sensor 400 can be best met, and the sensing sensitivity and accuracy can be improved. Therefore, when the sealing member 300 and the sensor 400 are completely disposed, the orthographic projection area of the protrusion 310 on the cover 500 is 60% to 70% of the orthographic projection area of the sensor 400 on the cover 500, which has a better sensing result than the case where the sensor 400 is in contact with the entire surface of the cover 320.

To more clearly describe the manner in which the sealing member 300 and the sensor 400 are disposed in the nut 200, please refer to fig. 5 and 6, in which fig. 5 is a cross-sectional view of the ball screw of fig. 2 taken along a-a, and fig. 6 is a partial enlarged view of a region B in fig. 5. As shown in fig. 5 and 6, the flow channel C communicates with the opening O, the sealing member 300 and the sensor 400 are disposed in the opening O, and the sensing member 400 is disposed between the protrusion 310 and the cover plate 500. Thus, when the cooling fluid flows to generate pressure and feeds back to the sealing member 300, the sensor 400 can immediately detect a slight change in the fluid pressure and the corresponding flow rate because the size of the protrusion 310 corresponds to the effective sensing area of the sensor 400. In addition, since the sensor 400 is a piezoresistive sensor and is simply stacked with the sealing member 300, the sensor 400 does not require complicated processing, and time and cost required for mass production in industry can be saved.

It should be noted that, since the outer annular surface of the sealing portion 340 is designed as a conical surface, when the sealing element 300 is disposed in the opening O, a gap R is formed between the sealing portion 340 and the wall W of the corresponding opening, and the size of the gap R decreases from the sealing portion 340 toward the cover portion 320. As such, when the flow velocity of the coolant increases, the portion of the sealing portion 340 near the connection portion 330 expands outward, so that the contact area between the outer circumferential surface of the sealing portion 340 and the wall surface W increases, and the leakage prevention effect can be more reliably achieved.

On the other hand, as shown in fig. 6, when the components are arranged, the surface 510 of the cover plate 500 is coplanar with the end surface 220, so that the flatness of the overall appearance of the ball screw 10 is improved, and the ball screw is not easy to collide or interfere with other components.

Fig. 7 is a block diagram of electronic components of the ball screw of fig. 1, and fig. 8 is a flowchart illustrating steps of detecting the cooling fluid by the ball screw of fig. 7, please refer to fig. 7 and 8. In addition to the above components, the ball screw 10 of the present embodiment further includes a signal processing unit 600, a control unit 700, a memory unit 800 and a prompt unit 900, wherein the sensor 400, the signal processing unit 600, the control unit 700 and the memory unit 800 are electrically connected to each other, and the prompt unit 900 is electrically connected to the control unit 700. When the ball screw 10 is activated (step S01), the fluid flows in the channel C and generates a pressure (step S02), and the sensor 400 senses the pressure and outputs a raw signal to the signal processing unit 600 (step S03). In the present embodiment, the signal processing unit 600 includes a signal amplifier and an analog-to-digital converter, which can amplify and sample the raw signal measured by the sensor 400 to be converted into a digital signal, so as to facilitate the subsequent signal processing procedure. After the signal processing unit 600 receives the original signal, and the original signal is processed and converted as described above, a processed digital signal is outputted to the control unit 700 (step S04), and the memory unit 800 stores the processed digital signal (step S05) so as to more completely track the pressure or flow rate of the cooling fluid.

In order to make the user immediately know when the coolant flow rate is abnormal, the prompt unit 900 of the present embodiment determines the type of the output prompt signal according to the relationship between the digital signal and a predetermined signal preset by the system (step S06). When the error between the digital signal and the predetermined signal is within the threshold of ± 20% of the predetermined signal, that is, the absolute value of the error is less than 20% of the predetermined signal, which indicates that the flow rate of the cooling liquid and the corresponding pressure are in the normal range, the control unit 700 controls the prompt unit 900 to output a first prompt signal (step S07), such as a green light, to prompt the user that the current flow rate of the cooling liquid is in the normal state; when the error amount between the digital signal and the predetermined signal is between the threshold of 20% to 40% of the predetermined signal or between-20% to-40% of the predetermined signal, that is, the absolute value of the error amount is between 20% to 40% of the predetermined signal, which represents that the flow rate of the cooling liquid and the corresponding pressure are at risk of being too large or too small, the control unit 700 controls the prompting unit 900 to output a second prompting signal (step S08), such as a yellow light, to prompt the user that the current flow rate of the cooling liquid is in a state that needs attention; when the error between the digital signal and the predetermined signal exceeds the ± 40% threshold of the predetermined signal, that is, the absolute value of the error is greater than 40% of the predetermined signal, which indicates that the flow rate and the corresponding pressure of the coolant are abnormal, the control unit 700 controls the prompting unit 900 to output a third prompting signal (step S09), such as a red light, to prompt the user that the current flow rate of the coolant is dangerous, and the coolant needs to be immediately processed or the device is stopped.

In summary, the ball screw of the present invention can detect the flow rate and the corresponding pressure of the cooling fluid in the flow channel in real time by disposing the sensor on the sealing member, and convert the original signal into a digital signal through the signal processing unit for processing. In addition, since the sensor, the sealing member and the cover plate are simply stacked, the sensor can use a simple and sensitive piezoelectric sensor or a piezoresistive sensor, thereby saving the manufacturing cost and improving the sensing precision.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.