JPH0643583Y2 - Magnetic fluid sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a magnetic fluid sealing device that seals various fluids by using magnetic fluid.

[Conventional technology]

The inventor of the present application previously made the magnetic pole pieces (4) provided at both ends of a magnetic source such as a permanent magnet (3) close to a mating member such as the shaft (1) as illustrated in FIG. The magnetic fluid (6) is placed in the gap (5) formed between the pole piece (4) and the mating member.
A magnetic fluid sealing device in which a magnetic fluid is interposed by means of a magnetic force is provided with an electronic cooling element (8) used for both heating and cooling of the magnetic fluid (6). But (actual exploitation 64-46580
The present invention is a further improvement of this prior application device.

[Problems to be solved by the device]

That is, in the above-mentioned prior application device, the electronic cooling element (8)
Switching between heating and cooling by means of switching the direction of the electric current supplied from the DC power supply to the electronic cooling element (8) by the changeover switch,
It was inconvenient because the user had to manually operate the changeover switch as needed, and the user had to constantly attend when the operating conditions of the equipment changed frequently. . In FIG. 4, reference numeral (2) is a housing, (7) is a magnetic circuit, (9) is a heat conductive plate, (10) is a lead wire, and (11) is a heat insulating material.

[Means for Solving the Problems]

In view of the above points, the present invention was devised to solve the problems remaining in the prior application device, and in order to achieve this object, it is provided at both ends of a magnetic force source such as a permanent magnet (3). The magnetic pole piece (4) is brought close to the mating member such as the shaft (1), and the magnetic fluid (6) is magnetically interposed in the gap (5) formed between the magnetic pole piece (4) and the mating member. In a magnetic fluid seal device, an electronic cooling element (8) used for both heating and cooling of the magnetic fluid (6), a variable current power source for supplying a current to the electronic cooling element (8), and the variable DC / DC. A relay-type open / close switch for turning on / off a current supplied from a power source to the electronic cooling element (8) and a relay-type switch for switching the direction of the current supplied from the variable DC power source to the electronic cooling element (8). Switch and the other part Sensor for detecting the presence or absence of rotation of the other member, a time sensor for detecting a rotation stop duration of the mating member, a temperature sensor for detecting the temperature of the magnetic fluid (6), the rotation sensor, the time sensor and the temperature sensor. A control device that controls the operation of the relay-type open / close switch and the relay-type changeover switch in accordance with the detection signal and controls the current value supplied from the variable DC power supply.

[Action]

When a detection signal is sent from each of the rotation sensor, the time sensor, and the temperature sensor to the control device, the control device determines whether heating or cooling is necessary based on the detection signal. When it is determined that heating or cooling is necessary, the control device sends a signal to the relay-type opening / closing switch and the relay-type changeover switch to perform the opening / closing operation or the changeover operation, and at the same time, the variable DC power supply supplies the electronic cooling element (8 ) Is controlled, and heating and cooling are automatically performed.

〔Example〕

 Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and the same reference numerals are used for corresponding parts having the same structure as the prior application device shown in FIG.

That is, in addition to the configuration of the prior application device shown in FIG. 4, the magnetic fluid sealing device includes a variable DC power source (14) capable of constant current control by an external signal, and the variable DC power source (14).
A relay type opening / closing switch (15) for energizing and interrupting a current i supplied from the electronic cooling element (8) by an external signal, and a relay type changeover switch (16) for switching the direction of the current i by an external signal, A rotation sensor (17) for detecting the rotation speed N of the shaft (1), and the rotation sensor (17)
A time sensor (18) for detecting an elapsed time from when the detection signal SG1 (rotation speed N) of 0 becomes zero (when the rotation of the axis (1) is stopped), that is, the rotation stop duration of the axis (1). , A temperature sensor (1) embedded in the vicinity of the gap (5) of the pole piece (4) for detecting the temperature T of the magnetic fluid (6).
9) and the detection signals SG1, SG of the rotation sensor (17), the time sensor (18) and the temperature sensor (19).
2. Determine the necessity of heating or cooling from SG3 and the device power ON signal SG4 that tells whether the device (system) body that uses the magnetic fluid sealing device as a component is operating or stopped. Then, when it is determined that heating or cooling is necessary, or when it is determined that heating or cooling is no longer necessary, the relay type open / close switch (1
5) Send signals SG5, SG6, SG7 to relay type changeover switch (16) and variable DC power supply (14) to start, control and stop heating or cooling, and switch between heating and cooling and stop heating. In this case, the control device (20) is provided for outputting the start preparation end signal SG8 of the axis (1).

FIG. 2 is an enlarged view of the main part of FIG. 1 to show the internal structure and connection state of the electronic cooling element (8). A pair of electronic cooling elements (8) provided so as to be in contact with the outer side surface of the pole piece (4) are connected in series with each other, and when the relay type changeover switch (16) is on the cooling side (C side), A current i flows in the direction shown in FIG. 2 to cool one conductor (12) side, that is, the side of the heat conductive insulator (13) in contact with the pole piece (4). On the contrary, when the relay type changeover switch (16) is on the heating side (H side), the current i flows in the direction opposite to that shown in FIG. 2 and is in contact with the magnetic pole piece (4). )
The sides are heated.

Next, the operation of the present embodiment (operation of the control device (20))
A description will be given according to the flowchart in the figure.

First, in step S1, it is determined whether the device (system) body is in operation (device power ON) or not in operation (device power OFF) by the device power ON signal SG4 described above, and YES (device power ON) If there is, proceed to step S2, NO (device power OF
If it is F), step S1 is repeatedly executed again. In step S2, the signal SG1 from the rotation sensor (17), that is, the value of the rotation speed N is read, and the step to be subsequently executed
In S3, it is determined whether or not the rotation speed N is zero, that is, whether the shaft (1) is rotating or stopped, and YES
If (N = 0), the process proceeds to step S4, NO (N>
If it is 0), the process proceeds to step S15. In step S4, the signal SG3 from the temperature sensor (19), that is, the value of the magnetic fluid temperature T is read, and in step S5 subsequently executed, it is determined whether or not the magnetic fluid temperature T is lower than 60 ° C., and YES If (T <60 ° C.), the process proceeds to step S6. If NO (T ≧ 60 ° C.), it is determined that cooling is necessary, and the process proceeds to step S17 of the cooling process. In step S6, the signal SG2 from the time sensor (18), that is, the value of the rotation stop duration t of the axis (1) is read, and in step S7 executed subsequently, the rotation stop duration t.
YES (t ≧ 10hr)
If NO, it is determined that heating is necessary, and the process proceeds to step S8 of the heating process. If NO (t <10 hr), it is determined that heating is not necessary and the process proceeds to step S14. In step S8, the signal SG6 is sent to the relay type changeover switch (16) to switch the relay type changeover switch (16) to the heating side (H side), and in the subsequent step S9, the relay type open / close switch (15). To the relay type open / close switch (15) to turn it on. Then, in step S10, an appropriate value of the current i is set based on the difference between the magnetic fluid temperature T read in step S4 and the heating target value of 60 ° C., and the signal SG7 is set to the variable DC power supply. It is sent to (14) and the magnetic fluid (6) is heated while controlling the value of the current i. Subsequently, in step S11, the signal SG3 from the temperature sensor (19), that is, the value of the magnetic fluid temperature T is read again, and in the next step S12, it is determined whether or not the magnetic fluid temperature T has reached 60 ° C. Step
If YES (T ≧ 60 ° C.) in S12, the process proceeds to the next step S13, in which a signal SG5 is sent to the relay type opening / closing switch (15) to turn off the relay type opening / closing switch (15) to end the heating. NO in step S12 (T <60 ℃)
If so, the process returns to step S10 again, and step S11
Based on the difference between the value of the new magnetic fluid temperature T read in and the heating target value of 60 ° C, the appropriate value of the current i is reset, and the signal SG7 is sent to the variable DC power supply (14), The heating of the magnetic fluid (6) is continued. Step S8 above
In the process from S13 to S13, the axis (1) is operated for a long time (1 in this embodiment).
After stopping (0 hours or more), the magnetic fluid (6) required for restarting is automatically heated. When step S13 ends, in step S14, a start preparation end signal SG8 is output to notify the device (system) main body that the preparation for restarting the axis (1) is completed, and then the process proceeds to return and returns to start again.

Next, step S15 executed when NO (rotational speed N> 0) in step S3 will be described. In step S15, as in step S4, the temperature sensor (19)
From the signal SG3, that is, the value of the magnetic fluid temperature T, is read, and in step S16 subsequently executed, it is determined whether the magnetic fluid temperature T is 30 ° C. or higher. Step S1
If YES in 6 (T ≧ 30 ° C.), it is determined that cooling is necessary, and the process proceeds to step S17 of the cooling process, where N
When it is O (T <30 ° C), it is judged that there is no need for cooling, and it proceeds to return and returns to start again. Step
In S17, a signal SG6 is sent to the relay type changeover switch (16) to switch the relay type changeover switch (16) to the cooling side (C side), and in the subsequent step S18, a signal is given to the relay type open / close switch (15). Send SG5 to turn on the relay type open / close switch (15). Then, in step S19, an appropriate value of the current i is set in accordance with the difference between the magnetic fluid temperature T read in step S15 and the cooling target value of 30 ° C., and the signal SG7 is set to the variable DC power supply ( 14) to cool the magnetic fluid (6) while controlling the value of the current i. Then, in step S20, the signal SG3 from the temperature sensor (19), that is, the value of the magnetic fluid temperature T is read again,
In step S21, it is determined whether the magnetic fluid temperature T has become 30 ° C. or lower. YES (T in step S21
In the case of ≦ 30 ° C., the process proceeds to the next step S22, the signal SG5 is sent to the relay type opening / closing switch (15) to turn off the relay type opening / closing switch (15), and the cooling is finished. If NO (T> 30 ° C.) in step S21, the process returns to step S19 again, and is appropriate based on the difference between the new magnetic fluid temperature T read in step S20 and the cooling target value of 30 ° C. The value of current i is reset and its signal SG
7 is sent to the variable direct current power source (14) to continue cooling the magnetic fluid (6). In the process of steps S17 to S22 described above, the cooling required when the temperature of the magnetic fluid (6) rises is performed. Upon completion of step S22, the process proceeds to return and returns to start again.

Thus, based on the above flow, the controller (20) automatically determines whether or not heating and cooling are necessary,
Accordingly, heating or cooling is started, controlled and stopped, and heating and cooling are switched.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the embodiment of the present invention is not limited to the above embodiment. For example, in the above-mentioned embodiment, the electronic cooling element (8) has the same structure as that of the prior application device shown in FIG. 4, but various conventionally known electronic cooling elements can be used. Also, the operation flow is not limited to that shown in FIG. 3, and the type of magnetic fluid (6) and the gap (5)
It is possible to operate with various flows that have been changed or improved depending on the magnitude and gradient of the magnetic field of the magnetic field, or the state of the operating environment of the magnetic fluid sealing device (system operating conditions using the magnetic fluid sealing device). Is.

[Effect of device]

As described above, according to the magnetic fluid sealing device of the present invention, the control device automatically determines whether or not heating or cooling is necessary, and operates the relay type opening / closing switch and the relay type changeover switch. By controlling the current value supplied from the variable DC power supply, heating and cooling can be performed automatically. Therefore, unlike the prior application device, it is not necessary for the user to manually operate the changeover switch to perform heating or cooling after determining the necessity of heating or cooling, and unmanned operation can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory view of a magnetic fluid sealing device according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of the magnetic fluid sealing device.
FIG. 3 is a flow chart showing the operation of the magnetic fluid sealing device, and FIG. 4 is an explanatory view of the magnetic fluid sealing device according to the conventional example. (1) ...... Shaft, (2) ...... Housing, (3) ...... Permanent magnet (4) ...... Magnetic pole pieces, (5) ...... Gap, (6) ...... Magnetic fluid (7) ...... Magnetic circuit , (8) …… Electronic cooling element (9) …… Heat conduction plate, (10) …… Lead wire, (11) ……
Insulation (12) …… conductor, (13) …… thermally conductive insulator (14) …… variable DC power supply, (15) …… relay type opening / closing switch (16) …… relay type changeover switch, (17 ) …… Rotation sensor (18) …… Time sensor, (19) …… Temperature sensor (20) …… Control device

Claims (1)

[Scope of utility model registration request] 1. A magnetic pole piece (4) provided at both ends of a magnetic force source such as a permanent magnet (3) is brought close to a mating member such as an axis (1),
In a magnetic fluid seal device in which a magnetic fluid (6) is magnetically interposed in a gap (5) formed between the magnetic pole piece (4) and a mating member, both heating and cooling of the magnetic fluid (6) are performed. Electronic cooling element used for the (8)
And a variable DC power supply (14) for supplying a current to the electronic cooling element (8), and a relay type for energizing and blocking the current supplied from the variable DC power supply (14) to the electronic cooling element (8) An open / close switch (15), a relay-type changeover switch (16) for changing the direction of the current supplied from the variable DC power supply (14) to the electronic cooling element (8), and the presence or absence of rotation of the mating member are detected. A rotation sensor (17),
A time sensor (18) for detecting the rotation stop duration of the mating member, a temperature sensor (19) for detecting the temperature of the magnetic fluid (6), the rotation sensor (17), the time sensor (18) and the temperature. A control device for controlling the operation of the relay type open / close switch (15) and the relay type changeover switch (16) according to the detection signal of the sensor (19) and for controlling the current value supplied from the variable DC power source (14). (20)
And a magnetic fluid sealing device.