KR102193421B1 - Ball screw - Google Patents

Abstract

The present invention relates to a ball screw suitable for sensing coolant, including a screw, a nut, a plurality of sealing members, a sensor, a signal processing unit, and a cover. The nut includes a body and a cross section. A through hole and a flow path are installed in the body. The nut is screwed into the screw through the through hole. A plurality of openings are provided in the cross section. The plurality of openings communicate with the flow path. The plurality of sealing members are disposed within the plurality of openings. The sensor is disposed on one of the plurality of sealing members, senses the pressure of the coolant, and outputs an original signal. The signal processing unit is electrically connected to the sensor, receives the original signal, and converts the original signal into a digital signal. The cover is disposed on the sensor and fixedly installed on the nut.

Description

Ball screw {BALL SCREW}

The present invention relates to a ball screw, and more particularly, to a ball screw for sensing a flow rate or pressure of a coolant through a sensor disposed on a sealing member.

Screws are quite common machinery in the industrial field. In general, when the screw and the nut disposed on the screw operate, the relative motion between each other easily generates a large amount of heat, so the operator generally first pours a lubricant on the screw to reduce the frictional resistance between the members or A flow path is installed inside the nut to continuously remove heat by the flow of the coolant. However, if the flow rate of the cooling liquid is insufficient, the generated heat cannot be removed smoothly, and there is a fear that the temperature of the member will continuously rise, and if there is too much cooling liquid, the pipeline may rupture and spread to other members that must maintain a dry state. Therefore, it is an important task to check the real-time flow rate of the cooling liquid.

In order to solve the above problem, in the prior art, there is a design in which a sensor is disposed inside a nut. For example, in Taiwan Patent Publication No. I572797, a double nut for detecting a preload by arranging an annular force sensor at the lower end of the annular variable platform. The ball screw has been disclosed, and the pressure of the fluid can be sensed by pressing the opposite sides of the two nuts. However, whether it is an annular variable platform or an annular force sensor, it is difficult to process, and the manufacturing cost also increases accordingly.

The present invention provides a ball screw that senses a flow rate or pressure of a coolant in real time through a sensor disposed on a sealing member, and the sensor does not require complicated processing, thereby reducing cost.

The ball screw of the present invention is suitable for sensing the cooling liquid, and includes a screw, a nut, a plurality of sealing members, a sensor, a signal processing unit, and a cover. The nut includes a body and a cross section, a through hole and a flow path are installed in the body, the nut is screwed into the screw through the through hole, a plurality of openings are installed in the cross section, and the plurality of openings are It communicates with the euro. The plurality of sealing members are disposed in the plurality of openings. The sensor is disposed on one of the plurality of sealing members, senses the pressure of the coolant, and outputs an original signal. The signal processing unit is electrically connected to the sensor, receives the original signal, and converts the original signal into a digital signal. The cover is placed on the sensor and fixed to the nut.

Preferably, one of the plurality of sealing members further includes a protrusion, and the sensor is disposed on the protrusion. Through this, the pressure fed back to the sealing member by the cooling liquid is more effectively transmitted to the sensor.

Preferably, the orthographic area on the cover of the protrusion is 60 to 70% of the orthographic area on the cover of the sensor. Through this, detection sensitivity and accuracy can be improved by making it most suitable for the effective detection area of the sensor.

Preferably, the ball screw further comprises a control unit and a memory unit, the sensor, the signal processing unit, the control unit and the memory unit are electrically connected to each other, the signal processing unit outputs a digital signal to the control unit, and the memory unit By storing digital signals, it more completely tracks the pressure or flow rate of the coolant.

Preferably, the ball screw further comprises a notification unit, the notification unit is electrically connected to the control unit, and if the error amount between the digital signal and the predetermined signal is within ±20% of the predetermined signal, the notification unit is the first When the alarm signal is output and the error amount is between 20% to 40% threshold value or -20% to 40% threshold value of the predetermined signal, the alarm unit outputs a second alarm signal, and the error amount is ±40% of the predetermined signal. When the% threshold is exceeded, the notification unit outputs a third notification signal. Through this, it is possible to inform the user of the current flow rate state of the coolant in real time.

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

Preferably, the plurality of sealing members are arranged symmetrically along the circumferential direction of the nut, and the surface and the cross section of the cover are the same plane. Through this, the flatness of the overall appearance of the present invention can be improved, and collision or interference with other members does not easily occur.

1 is a perspective view schematically showing a ball screw according to an embodiment of the present invention.
2 is an exploded view of some elements of the ball screw of FIG. 1.
3 is a perspective view schematically showing the sealing member of FIG. 2.
4 is a side view of the sealing member of FIG. 3.
5 is a cross-sectional view taken along the AA cross-section of the ball screw of FIG. 2.
6 is a partially enlarged view of area B of FIG. 5.
7 is a block diagram of electronic elements of the ball screw of FIG. 1.
8 is a flowchart illustrating a step of sensing a cooling liquid by the ball screw of FIG. 7.

With respect to the foregoing and other technical content, features and effects of the present invention, it will become more apparent by combining the detailed description of the preferred embodiments of the following reference drawings. The direction terms such as up and down, left and right, and front and rear mentioned in the following examples refer to the directions of the accompanying drawings only. Accordingly, the directional terms used are for illustration only, not for limiting the present invention.

1 is a perspective view schematically showing a ball screw according to an embodiment of the present invention, and FIG. 2 is an exploded view of some elements of the ball screw of FIG. 1, and referring to FIGS. 1 and 2, the ball screw 10 of this embodiment is It includes a screw 100, a nut 200, a plurality of sealing members 300, a sensor 400 and a cover 500. The nut includes a body 210 and an end face 220, a through hole H and a flow path are installed in the body 210, a plurality of openings O are installed in the end face 220, and the plurality of The opening (O) of the channel communicates with the flow path, the plurality of sealing members 300 are disposed inside the plurality of openings (O), and the sensor 400 is one of the plurality of sealing members 300 ( 300), the cover 500 is disposed on the sensor 400 and fixedly installed on the nut 200.

In detail, the nut 200 is screwed into the screw 100 through the through hole H, and a thread is installed inside the through hole H, so that the nut 200 has a through hole H ) It is possible to move relative to the screw 100 through the inner thread. Since high heat may be generated during the relative movement of the nut and the screw, a cooling liquid is disposed in the flow path of the nut 200 to lower the temperature of the nut 200. Since the opening O communicates with the flow path and the plurality of sealing members 300 are disposed in the plurality of openings O, the pressure generated by the cooling liquid can be directly fed back to the sealing member 300. As shown in Figure 2, the shape of the sealing member 300 corresponds to the opening (O), in order to prevent the cooling liquid from leaking because the sealing member 300 is not completely sealed, the sealing member 300 has a gasket ( 350) is further arranged to more closely engage the opening (O). When the arrangement of the sealing member 300 is completed, in order to detect the flow rate of the cooling liquid, the sensor 400 is disposed on one of the sealing members 300, and the sealing member ( 300) to sense the feedback pressure. When the arrangement of the sensor 400 is completed, the cover 500 is disposed on the sensor 400, and the cover 500 is fixedly installed to the nut 200 through a fastening member such as a bolt.

For reference, as shown in FIG. 2, the plurality of sealing members 300 of the present embodiment are arranged symmetrically along the circumferential direction of the nut 200, and this arrangement occurs due to the difference in sealing degrees at different positions. It is possible to reduce the pressure change of the coolant to be used.

Figure 3 is a perspective view schematically showing the sealing member of Figure 2, Figure 4 is a side view of the sealing member of Figure 3, referring to Figures 3 and 4, in this embodiment, the plurality of sealing members 300 Each has a cover part 320, a connection part 330 and a sealing part 340, the connection part 330 is connected to the cover part 320 and the sealing part 340, the sealing member 300 is a sealing part A 340 is disposed within the opening O in such a way that it faces the opening O. When the sealing member 300 is disposed inside the opening (O), the gasket 350 is disposed between the cover part 320 and the sealing part 340, and for this purpose, the size of the connection part 330 is the cover part 320 ) And the sealing part 340 is designed slightly smaller than that, when the gasket 350 is fitted into the connection part between the cover part 320 and the sealing part 340, the sealing member 300 is separated due to vertical sliding. Do not. In other words, when the arrangement of the sealing member 300 is complete, the orthogonal projection area on the cover 500 of the connection part 330 is the orthogonal projection area on the cover part 320 and the cover 500 of the sealing part 340 Less than

For reference, as shown in FIG. 4, the outer peripheral surface of the sealing part 340 is designed as a conical surface, and this design allows the sealing member 300 to increase the flow rate of the cooling liquid. By making it more closely adhered to the wall surface, a better anti-leakage effect is achieved, and related details will be described later.

In this embodiment, the sensor 400 is a piezoresistive sensor and may generate a corresponding electric resistance signal by receiving pressure from the sealing member 300. The sealing member 300 on which the sensor 400 is disposed in this embodiment further includes a protrusion 310 so that the pressure fed back to the sealing member 300 by the cooling liquid is more effectively transmitted to the sensor 400, and 400 is disposed on the protrusion 310. According to the test results through the experiment, when the size of the protrusion 310 is designed to be 60% to 70% of the sensor 400, it is most suitable for the effective sensing area of the sensor 400, and detection sensitivity and accuracy can be improved. have. Therefore, when the arrangement of the sealing member 300 and the sensor 400 is completed, the orthogonal projection area on the cover 500 of the protrusion 310 is 60% of the orthogonal projection area on the cover 500 of the sensor 400 ~70%, and this arrangement has a better detection result than contacting the sensor 400 with the surface of the entire cover part 320.

In order to more clearly describe the state in which the sealing member 300 and the sensor 400 are disposed in the nut 200, refer to FIGS. 5 and 6, and FIG. 5 is a cross-sectional view of the ball screw of FIG. 2 taken along the AA cross-section. And FIG. 6 is a partially enlarged view of area B of FIG. 5. 5 and 6, the flow path C is in communication with the opening O, the sealing member 300 and the sensor 400 are disposed in the opening O, and the sensor 400 is a protrusion ( It is disposed between 310) and the cover 500. Through this, when pressure is generated by the flow of the coolant and is fed back to the sealing member 300, since the size of the protrusion 310 corresponds to the effective sensing area of the sensor 400, the sensor 400 Subtle changes in the corresponding flow rate can be detected immediately. In addition, since the sensor 400 is a piezoresistive sensor and is a simple stacking relationship with the sealing member 300, the sensor 400 does not require complicated processing, so it is possible to save time and cost required for industrial mass manufacturing. .

For reference, the outer circumferential surface of the sealing part 340 is designed as a conical surface, and when the sealing member 300 is disposed inside the opening O, the gap R between the sealing part 340 and the wall surface W of the corresponding opening ) Is present, and the size of the gap R gradually decreases in a direction from the sealing part 340 toward the cover part 320. Through this, when the flow rate of the cooling liquid increases, the portion close to the connection part 330 of the sealing part 340 expands to the outside, and the contact area between the outer circumferential surface of the sealing part 340 and the wall surface W is increased. It can certainly reach the anti-leak effect.

On the other hand, as shown in Fig. 6, when the arrangement of each element is completed, the surface 510 and the end surface 220 of the cover 500 are the same plane, whereby the flatness of the overall appearance of the ball screw 10 It can be improved, and collision or interference with other members does not occur easily.

7 is a block diagram of electronic elements of the ball screw of FIG. 1, and FIG. 8 is a flow chart of a step in which the ball screw of FIG. 7 detects a cooling liquid. Referring to FIGS. 7 and 8, in addition to the member, the ball of the present embodiment The screw 10 further includes a signal processing unit 600, a control unit 700, a memory unit 800, and a notification unit 900, and a sensor 400, a signal processing unit 600, and a control unit 700 ) And the memory unit 800 are electrically connected to each other, and the notification unit 900 is electrically connected to the control unit 700. After the ball screw 10 is operated (step S01), the fluid flows in the flow path (C) to generate pressure corresponding thereto (step S02), and at this time, the sensor 400 detects the pressure and processes the original signal. Output to the unit 600 (step S03). In this embodiment, the signal processing unit 600 includes a signal amplifier and an analog-to-digital converter, amplifies the original signal sensed by the sensor 400 and converts it by sampling into a digital signal, which is advantageous for a subsequent signal processing process. To be. The signal processing unit 600 receives the original signal, undergoes the above-described processing and conversion, and outputs the processed digital signal to the control unit 700 (step S04), and at the same time, the memory unit 800 By storing the digital signal (step S05), the pressure or flow rate of the coolant is more completely tracked.

In order for the user to know immediately when an abnormality occurs in the flow rate of the coolant, the notification unit 900 of the present embodiment is based on the relationship between the error amount of the digital signal and the predetermined signal preset in the system and the predetermined signal (step S06), Determine the type of the output notification signal. If the error amount between the digital signal and the predetermined signal is within ±20% of the predetermined signal, that is, the absolute value of the error amount is less than 20% of the predetermined signal amount, it means that the flow rate and corresponding pressure of the coolant are in the normal range. At this time, the control unit 700 controls the notification unit 900 to output a first notification signal such as a green light signal (step S07) to inform the user that the current flow rate of the coolant is in a normal state, If the error amount of the signal is between 20% to 40% threshold value or -20% to 40% threshold value of the predetermined signal, that is, the absolute value of the error amount is 20% to 40% of the predetermined signal, the flow rate and corresponding pressure of the coolant are It means that there is a risk of being too large or too small. At this time, the control unit 700 controls the notification unit 900 to output a second notification signal such as a yellow light signal (step S08), and the current flow rate of the coolant to the user Informs that this is a state to be paid attention to, and if the error amount between the digital signal and the predetermined signal exceeds the ±40% threshold value of the predetermined signal, that is, the absolute value of the error amount is greater than 40% of the predetermined signal amount, the flow rate of the coolant and the corresponding It means that an abnormality has occurred in the pressure, and at this time, the control unit 700 controls the notification unit 900 to output a third notification signal such as a red light signal (step S09), and the current flow rate of the coolant is dangerous to the user. Therefore, it is advised that the coolant must be treated immediately or the device must be shut down.

In summary, the ball screw of the present invention can detect the flow rate and corresponding pressure of the coolant in the flow path in real time by arranging a sensor on the sealing member, and it is advantageous for signal processing since the original signal is converted into a digital signal through the signal processing unit. Do. In addition, since the sensor, the sealing member, and the cover are simply stacked, the sensor can use a simple and sensitive piezoelectric sensor or a piezoresistive sensor, thereby reducing manufacturing costs and improving detection accuracy.

The above description is merely a preferred embodiment of the present invention, and all equivalent changes and modifications based on the claims of the present invention belong to the protection scope of the present invention.

10: ball screw
100: screw
200: nut
210: main body
220: cross section
300: sealing member
310: protrusion
320: cover portion
330: connection
340: sealing part
350: gasket
400: sensor
500: cover
510: surface
600: signal processing unit
700: control unit
800: memory unit
900: notification unit
C: Euro
H: through hole
O: opening
R: gap
W: wall

Claims (5)

In the ball screw sensing the coolant,
screw;
It includes a body and a cross-section, and a through hole and a flow path are installed in the body, and are screwed into the screw through the through hole, a plurality of openings are installed in the cross-section, and the plurality of openings are A nut in communication with the flow path;
A plurality of sealing members disposed in the plurality of openings;
A sensor disposed on one of the plurality of sealing members to sense the pressure of the coolant and output an original signal;
A signal processing unit electrically connected to the sensor, receiving the original signal, and converting the original signal into a digital signal; And
A ball screw disposed on the sensor and comprising a cover fixedly installed on the nut. The method of claim 1,
One of the sealing members further includes a protrusion, and the sensor is disposed on the protrusion. The method of claim 2,
The orthogonal projection area on the cover of the protrusion is 60% to 70% of the orthographic area on the cover of the sensor. The method of claim 1,
Further comprising a control unit and a memory unit, the sensor, the signal processing unit, the control unit and the memory unit are electrically connected to each other, the signal processing unit outputs the digital signal to the control unit, the memory The unit stores the digital signal, ball screw. The method of claim 4,
Further comprising a notification unit, the notification unit is electrically connected to the control unit, and when the error amount between the digital signal and the predetermined signal is within ±20% threshold of the predetermined signal, the notification unit outputs a first notification signal, and When the vehicle is between 20% to 40% threshold or -20% to 40% threshold of the predetermined signal, the notification unit outputs a second notification signal, and when the error amount exceeds the ±40% threshold of the predetermined signal, The notification unit outputs a third notification signal, a ball screw.

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