JP6367144B2 - Cylinder rod device - Google Patents

Description

  The present invention relates to a cylinder rod device.

  As a conventional cylinder rod device, a cylinder rod device provided in a Stirling refrigerator is known. (For example, refer to Patent Document 1). The cylinder rod device described in Patent Literature 1 includes a cylinder, a piston (rod), a movable coil attached to the piston, and a magnetic circuit. During the operation of the cylinder rod device, an alternating current flows through a conductive wire constituting the movable coil, so that the piston reciprocates together with the movable coil in the magnetic field created by the magnetic circuit. On the other hand, when the operation of the cylinder rod device is stopped, the conductive wire is short-circuited by the switch. For this reason, even when a large vibration is applied from the outside, a force acts on the movable coil in a direction in which the vibration is suppressed. Thereby, the damage of the components resulting from the vibration from the outside is suppressed.

Japanese Patent Laid-Open No. 05-10617

  Since the cylinder rod device as described above requires a switching device to short-circuit the conductive wires, a simpler configuration is required.

  An object of this invention is to provide the cylinder rod apparatus which can suppress the damage of the components resulting from the vibration from the outside by simple structure.

  A cylinder rod device according to the present invention includes a cylinder, a rod that reciprocates inside the cylinder, a bobbin provided at an end of the rod opposite to the cylinder, and wound around the bobbin, and the axial direction of the bobbin A first coil winding and a second coil winding adjacent to each other, an annular magnet disposed around the bobbin and opposed to the first coil winding and the second coil winding, and a first coil winding And a power supply for supplying power to the second coil winding, the first coil winding and the second coil winding being wound in the same direction, and one end side of each other and the other end side of each other They are electrically connected to each other, and the number of turns of the second coil is smaller than the number of turns of the first coil.

  In the cylinder rod device according to the present invention, the first coil winding and the second coil winding are wound in the same direction. For this reason, during operation of the apparatus, the first coil winding and the second coil winding contribute to the reciprocating movement of the rod as one coil winding. Further, in the first coil winding and the second coil winding, one end sides of each other and the other end sides of each other are electrically connected to each other. That is, the first coil winding and the second coil winding are short-circuited. For this reason, when the operation of the apparatus is stopped, a force acts in a direction in which the vibration of the rod is suppressed even when a vibration is applied from the outside. At this time, induced currents in opposite directions are generated in the first coil winding and the second coil winding. However, since the number of turns of the second coil winding is smaller than the number of turns of the first coil winding, the mutual induced currents do not cancel each other out, and as a result, the vibration of the rod is suppressed. Force acts. As described above, in the cylinder rod device according to the present invention, it is possible to suppress damage to parts due to vibration from the outside with a simple configuration.

  According to the present invention, damage to parts due to external vibration can be suppressed with a simple configuration.

It is a schematic sectional drawing of the Stirling refrigerator provided with the compressor which is one Embodiment of the cylinder rod apparatus which concerns on this invention. It is the schematic of the compressor shown in FIG. It is a figure which shows the operation | movement at the time of a driving | operation of a compressor. It is a figure which shows the operation | movement at the time of the operation stop of a compressor. It is a figure which shows the operation | movement at the time of the operation stop of a compressor.

  Embodiments of the present invention will be described with reference to the drawings. However, the following embodiments are exemplifications for explaining the present invention and are not intended to limit the present invention to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  FIG. 1 is a schematic cross-sectional view of a Stirling refrigerator provided with an embodiment of a cylinder rod device. As shown in FIG. 1, the Stirling refrigerator 100 includes a cold head (cold finger) 101, a compressor (cylinder rod device) 1, and a connecting pipe 102 that connects them. The Stirling refrigerator 100 reciprocates a working gas such as helium between the compressor 1 and the cold head 101 to generate cryogenic cold.

  The compressor 1 includes a housing 2, a cylinder 3, a rod 4, a bobbin 5, a first coil winding 6, a second coil winding 7, a magnet 8, and a power source 9.

  The housing 2 contains a cylinder 3, a rod 4, a bobbin 5, a first coil winding 6, a second coil winding 7, and a magnet 8. The upper part of the housing 2 is connected to the connecting pipe 102. The housing space of the housing 2 communicates with the cold head 101 via the connecting pipe 102 so that the working gas can flow between them. The cylinder 3 has a cylindrical shape and is attached to the upper portion of the housing 2. The rod 4 has a cylindrical shape and is located inside the cylinder 3. The rod 4 reciprocates inside the cylinder 3.

  The bobbin 5 has a cylindrical shape whose outer diameter is larger than that of the rod 4 and is made of a nonmagnetic material. The bobbin 5 is provided at the end of the rod 4 opposite to the cylinder 3. The bobbin 5 and the rod 4 are coaxial. The bobbin 5 is connected to a support spring 11 attached to the lower part of the housing 2. When the bobbin 5 is moved to the upper side of the housing 2, a force toward the lower part of the housing 2 acts on the bobbin 5 by the support spring 11.

  The first coil winding 6 and the second coil winding 7 are wound around the bobbin 5. Details of the first coil winding 6 and the second coil winding 7 will be described later. The magnet 8 has an annular shape. The magnet 8 is disposed around the bobbin 5 and is opposed to the first coil winding 6 and the second coil winding 7 so as to be spaced outward in the circumferential direction. The magnet 8 constitutes a magnetic circuit together with the yoke 12 arranged in the housing 2. In the gap S between the magnet 8 and the first coil winding 6 and the second coil winding 7, a permanent magnetic field exists in the plane direction orthogonal to the axial direction of the bobbin 5.

  The power source 9 supplies power (more specifically, a sinusoidal alternating current) to the first coil winding 6 and the second coil winding 7. The power source 9 is disposed outside the housing 2. The power source 9 is electrically connected to the end portions of the first coil winding 6 and the second coil winding 7 via the connection terminals 13 and 14.

  Next, the first coil winding 6 and the second coil winding 7 will be described in detail. FIG. 2 is a schematic diagram of the compressor shown in FIG. The number of turns in each of the first coil winding 6 and the second coil winding 7 is set to be smaller than the actual number for convenience of illustration.

  As shown in FIG. 2, the first coil winding 6 and the second coil winding 7 are located adjacent to each other in the axial direction of the bobbin 5. The second coil winding 7 is located closer to the rod 4 in the axial direction of the bobbin 5 than the first coil winding 6. More specifically, the first coil winding 6 and the second coil winding 7 are wound around the bobbin 5 so as to be clockwise toward the rod 4 side when viewed from the rod 4 side in the axial direction of the bobbin 5. It has been. That is, the first coil winding 6 and the second coil winding 7 are wound around the bobbin 5 in the same direction.

  The number of turns of the second coil winding 7 is smaller than the number of turns of the first coil winding 6. When the ratio of the number of turns of the first coil winding 6 and the number of turns of the second coil winding 7 is 4: 1, the number of turns of the first coil winding 6 is about 80, for example. The number of turns of the winding 6 is, for example, about 20. When the number of turns of the second coil winding 7 is extremely small, the electric resistance of the second coil winding 7 becomes too small, and a current exceeding the allowable current can flow to the second coil winding 7. For this reason, it is desirable that the number of windings is as exemplified above.

  One end sides of the first coil winding 6 and the second coil winding 7 are electrically connected via a connection terminal 13 of a power source 9. Similarly, the other end sides of the first coil winding 6 and the second coil winding 7 are also electrically connected via the connection terminal 14 of the power source 9. That is, the first coil winding 6 and the second coil winding 7 are short-circuited via the connection terminals 13 and 14 to form one closed loop.

  Then, the operation | movement at the time of the driving | operation of the compressor 1 is demonstrated using FIG. First, AC power is applied from the power source 9 to each of the first coil winding 6 and the second coil winding 7. In the first coil winding 6 and the second coil winding 7, currents A1 and B1 flow from the connection terminal 13 side to the connection terminal 14 side, respectively. The currents A1 and B1 flow counterclockwise when the first coil winding 6 and the second coil winding 7 are viewed from the rod 4 side. Thereby, the Lorentz force toward the rod 4 side acts on the first coil winding 6 and the second coil winding 7 due to the interaction with the permanent magnetic field of the gap S.

  More specifically, the Lorentz force toward the rod 4 acts on the first coil winding 6. Similarly, Lorentz force toward the rod 4 side also acts on the second coil winding 7. That is, the rod 4 moves toward the cylinder 3 by the resultant force of the Lorentz force acting on the first coil winding 6 and the Lorentz force acting on the second coil winding. On the other hand, the rod 4 reaching the upper side of the housing 2 is pulled back to the lower side of the housing 2 by the support spring 11 because the Lorentz force becomes small. The rod 4 reciprocates in the cylinder 3 by such continuous movement.

  Subsequently, the operation when the compressor 1 is stopped will be described with reference to FIGS. 4 and 5. In this case, the application of AC power from the power source 9 is stopped. For this reason, no current flows through the first coil winding 6 and the second coil winding 7. In this state, when vibration is applied from the outside, the assembly composed of the rod 4, the bobbin 5, the first coil winding 6, and the second coil winding 7 is vibrated.

  If this assembly starts to move to the side opposite to the rod 4 due to vibration, the first coil winding 6 and the second coil winding 7 are connected to the connection terminal 13 side as shown in FIG. Inductive currents A2 and B2 are generated toward the connection terminal 14 side. That is, induced currents A 2 and B 2 in the same direction as the currents A 1 and B 1 that flow during operation of the compressor 1 flow through the first coil winding 6 and the second coil winding 7.

  Here, the first coil winding 6 and the second coil winding 7 are short-circuited. For this reason, for example, the induced current A <b> 2 generated in the first coil winding 6 flows also in the second coil winding 7 through the connection terminals 13 and 14. In this case, on the second coil winding 7, the induced current B2 generated in the second coil winding 7 and the induced current A2 generated in the first coil winding 6 are in opposite directions. For this reason, the mutual induction currents A2 and B2 cancel each other.

  Here, the number of turns of the second coil winding 7 is smaller than the number of turns of the first coil winding 6. For this reason, the mutual induction currents A2 and B2 do not completely cancel each other. That is, the induced current A2 generated in the first coil winding 6 having a large number of turns is larger than the induced current B2 generated in the second coil winding 7 having a small number of turns. Therefore, as shown in FIG. 5, among the induced current A <b> 2 generated in the first coil winding 6, the induced current A <b> 3 that has not been canceled by the second coil winding 7 remains. As a result, an induced current A3 flows in the first coil winding 6 from the connection terminal 13 side toward the connection terminal 14 side, and in the second coil winding 7 from the connection terminal 14 side toward the connection terminal 13 side. Induced current A3 flows.

  At this time, a Lorentz force directed toward the rod 4 is generated in the first coil winding 6, and a Lorentz force directed toward the opposite side of the rod 4 is generated in the second coil winding 7. However, since the number of turns of the first coil winding 6 is larger than the number of turns of the second coil winding 7, the Lorentz force toward the opposite side of the rod 4 is larger than the Lorentz force toward the opposite side of the rod 4. As a result, the rod 4 moves toward the cylinder 3 side. Based on the above principle, when the operation of the compressor 1 is stopped, Lorentz force acts in a direction in which vibration of the rod 4 is suppressed.

  As described above, in the compressor 1, the first coil winding 6 and the second coil winding 7 are wound in the same direction. For this reason, during the operation of the apparatus, the first coil winding 6 and the second coil winding 7 contribute to the reciprocating movement of the rod 4 as one coil winding. Moreover, in the 1st coil winding 6 and the 2nd coil winding 7, the mutual one end side and mutual other end side are electrically connected, respectively. That is, the first coil winding 6 and the second coil winding 7 are short-circuited. For this reason, when the operation of the apparatus is stopped, a force acts in a direction in which the vibration of the rod 4 is suppressed even when vibration is applied from the outside. At this time, induced currents A2 and B2 in opposite directions are generated in the first coil winding 6 and the second coil winding 7. However, since the number of turns of the second coil winding 7 is smaller than the number of turns of the first coil winding 6, the mutual induction currents A2 and B2 do not completely cancel each other. The force acts in the direction in which is suppressed. Thus, in the compressor 1, damage to components due to external vibration can be suppressed with a simple configuration.

  As mentioned above, although this embodiment was described, this invention is not limited to the said embodiment.

  For example, the winding direction of the first coil winding 6 and the second coil winding 7 may be reverse winding. Further, the positions of the first coil winding 6 and the second coil winding 7 in the axial direction of the bobbin 5 may be switched. That is, the configuration and arrangement of the first coil winding 6 and the second coil winding 7 may be appropriately changed according to the design conditions of the compressor 1.

  Further, the one end sides of the first coil winding 6 and the second coil winding 7 are electrically connected to each other at a position closer to the bobbin 5 than the connection terminal 13, for example, without passing through the connection terminal 13. May be. Similarly, the other end sides of the first coil winding 6 and the second coil winding 7 are also electrically connected to each other at a position closer to the bobbin 5 than the connection terminal 14 without passing through the connection terminal 14. May be.

  The cylinder rod device as described above can also be applied to a displacer, a cylinder, and the like provided in the cold head 101 of the Stirling refrigerator 100. Further, the cylinder rod device is not limited to the Stirling refrigerator, but can be widely applied to other refrigerators and further to other devices having a cylinder rod mechanism.

  DESCRIPTION OF SYMBOLS 3 ... Cylinder, 4 ... Rod, 5 ... Bobbin, 6 ... 1st coil winding, 7 ... 2nd coil winding, 8 ... Magnet, 9 ... Power supply.

Claims (1)

A cylinder,
A rod that reciprocates inside the cylinder;
A bobbin provided at an end of the rod opposite to the cylinder;
A first coil winding and a second coil winding wound around the bobbin and adjacent in the axial direction of the bobbin;
An annular magnet disposed around the bobbin and opposed to the first coil winding and the second coil winding;
A power source for supplying power to the first coil winding and the second coil winding,
The first coil winding and the second coil winding are wound in the same direction, and one end side of each other and the other end side of each other are electrically connected to each other,
The cylinder rod device, wherein the number of turns of the second coil winding is smaller than the number of turns of the first coil winding.

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