JP2008144611A - Thrmosensitive actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosensitive actuator generating a stroke corresponding to temperature up to a set temperature in regard to the thermosensitive actuator generating an output stroke according to an external temperature, and maintaining the output stroke to the constant set stroke without change when an atmospheric temperature or the external temperature rises exceeding the set temperature. <P>SOLUTION: A hard compression coil spring 40 is disposed between a first rod 15 with its tip part inserted in a spool 12 inserted in a thermosensitive case 10 filled with thermosensitive wax 11, and a second rod 28 slidably disposed in an outer case 10 to generate the output stroke. Up to the set temperature, the compression coil spring 40 is operated as a rigid body to transmit the stroke of the first rod 15 directly to the second rod 28, and after the second rod 28 generates the output stroke and abuts on a spring receiver 31 at the upper end, the output stroke of the first rod 15 is received by the deformation of the compression coil spring 40 to maintain the output stroke as it is the set stroke. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a temperature-sensitive actuator, and in particular, an extruded tube is inserted into a temperature-sensitive case filled with a temperature-sensitive substance, and a first rod having a base end portion inserted into the extruded tube is connected to the temperature-sensitive case. The present invention relates to a temperature-sensitive actuator that extrudes in response to expansion and contraction of a temperature-sensitive substance that accompanies temperature changes on the outside.

  For example, in Japanese Patent Application Laid-Open No. 2003-172248, a first chamber in a housing defined by a movable partition member is filled with a motive liquid having a high coefficient of thermal expansion, and a second working chamber is filled with a lubricating working liquid. The chamber is communicated with the working chamber of the cylinder, the partition member is compressed by the expansion force of the driving liquid as the temperature rises, the working liquid in the second chamber is moved to the working chamber, the piston is pushed, and a straight line corresponding to the temperature change An actuator is disclosed in which target devices are actuated by movement, and the stroke and force applied to the piston are arbitrarily set by the effective area ratio between the partition member and the piston.

  JP-A-8-247020 proposes a temperature-sensitive actuator using a shape memory alloy spring. Japanese Unexamined Patent Publication No. 9-313636 discloses a temperature sensitive actuator using temperature sensitive ferrite. Japanese Patent Application Laid-Open No. 8-136360 discloses a temperature sensitive member in which a temperature sensitive magnetic material is provided on the stator side so as to face the outer peripheral surface of the rotor with an air gap so as to obtain a stroke in the rotation direction. An actuator is disclosed.

This type of actuator takes out an output in accordance with a change in external temperature or ambient temperature. In particular, in the case of a temperature-sensitive actuator such as that disclosed in Japanese Patent Application Laid-Open No. 2003-172248, when the external temperature rises further than the set value, the overstroke is reduced. Will occur. In other words, the actuator generates an excessive stroke that is not necessary. This may cause an excessive load on the device to be used, or may cause a failure by strongly pressing the pressed portion. Therefore, conventionally, when an overstroke occurs due to an external temperature or an ambient temperature, such an overstroke is predicted in advance, and a limiter mechanism or the like is provided on the device side used by the actuator.
JP 2003-172248 A JP-A-8-247020 JP-A-9-313636 JP-A-8-136360

  The present invention is to provide a temperature-sensitive actuator that does not cause an overstroke exceeding a predetermined set stroke.

  Another object of the present invention is to provide a temperature-sensitive actuator in which it is not necessary to provide a limiter mechanism for absorbing overstroke on the equipment side to which the actuator is applied.

  Still another object of the present invention is to provide a temperature-sensitive actuator that does not cause an excessive stroke even when an unexpected temperature is applied to the actuator side.

  Still another object of the present invention is to provide a temperature-sensitive actuator in which the output stroke is maintained at the set stroke when a temperature equal to or higher than the set temperature is applied.

  The above-described problems and other problems of the present invention will be clarified by the technical idea of the present invention described below and the embodiments thereof.

The main invention of the present application is that an extruded tube is inserted into a temperature-sensitive case filled with a temperature-sensitive substance, and a first rod having a proximal end portion inserted into the extruded tube is used to change the temperature outside the temperature-sensitive case. In the temperature-sensitive actuator that is extruded according to the expansion and contraction of the temperature-sensitive substance accompanying
In addition to having a second rod that generates an output stroke in conjunction with the pushing operation of the first rod, a relief mechanism is provided between the first rod and the second rod, and the second rod is The present invention relates to a temperature-sensitive actuator, wherein when the first rod is further pushed out after moving a set stroke, the stroke of the first rod is absorbed by the relief mechanism.

  Here, the temperature sensitive substance may be a temperature sensitive wax. The extruded tube is a flexible cylindrical bag with a closed end, and the closed end of the tube is inserted into the temperature-sensitive case, and the first tube is opened from the opened proximal end side. A rod may be inserted into the tube. The relief mechanism is a compression coil spring interposed between the first rod and the second rod, and the elastic restoring force of the compression coil spring moves the set stroke of the second rod. The elastic force of the return spring of the second rod may be set larger than the elastic force of the second rod, and the compression coil spring may function as a rigid body while the second rod moves to a set stroke. The relief mechanism is a compression coil spring interposed between the first rod and the second rod, and the spring constant of the compression coil spring is greater than the spring constant of the return spring of the second rod. When the set load of the return spring is set larger than the set load of the compression coil spring constituting the relief mechanism and the first rod is pushed out, the compression coil constituting the relief mechanism is first set. When the spring is compressed and the elastic restoring force of the compression coil spring exceeds the elastic restoring force of the return spring, the stroke of the first rod may be transmitted to the second rod via the compression coil spring. The second rod is movably disposed in a cylindrical outer casing, and the second rod is disposed between the proximal end spring receiver of the second rod and the distal end spring receiver of the first rod. A compression coil spring constituting a relief mechanism may be interposed, and an output stroke of the first rod may be transmitted to the second rod via the compression coil spring.

  The main invention of the present application is that an extruded tube is inserted into a temperature-sensitive case filled with a temperature-sensitive substance, and the first rod having a proximal end portion inserted into the extruded tube is used to change the temperature outside the temperature-sensitive case. A temperature-sensitive actuator that extrudes in response to expansion and contraction of a temperature-sensitive substance, and has a second rod that generates an output stroke in conjunction with the pushing operation of the first rod, A relief mechanism is provided between the second rod and the stroke of the first rod is absorbed by the relief mechanism when the first rod is further pushed after the second rod has moved a set stroke. Is.

  Therefore, according to such a temperature-sensitive actuator, even if the first rod is further pushed after the second rod has moved by the set stroke, the stroke of the first rod is absorbed by the relief mechanism. The rod 2 does not change its output beyond the set stroke.

  The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 and FIG. 2 show the overall structure of the temperature-sensitive actuator of the present embodiment. This temperature-sensitive actuator has a cylindrical temperature-sensitive case 10 as shown in FIG. I have. A temperature sensitive wax 11 is filled in the temperature sensitive case 10. And the spool 12 which comprises the tube for extrusion from the upper opening of this temperature sensitive case 10 is inserted. The spool 12 is a rubber tube having a distal end side closed and a proximal end side opened. Such a tube is fixed to the temperature sensitive case 10 by a guide 13 attached to an opening on the inlet side of the temperature sensitive case 10.

  A first rod 15 is disposed so as to be inserted into the spool 12 from above. The first rod 15 is inserted through an insertion hole 14 that passes through the central portion of the guide 13 in the axial direction, and O-rings 16, 17, 18 are interposed between the insertion hole 14 and the first rod 15. So that the gap between the first rod 15 and the guide 13 is sealed.

  An outer casing 24 is attached to the upper part of the temperature sensitive case 10. The outer casing 24 is arranged coaxially with the temperature sensing case 10 and is connected to the upper end side of the temperature sensing case 10 via a connecting cylinder 25 that is slightly larger than the outer casing 24. A ring-shaped spacer 26 is disposed in the connecting cylinder 25 so as to receive the lower end of the outer casing 24. An O-ring 27 is fitted on the lower side of the spacer 26 and between the connecting cylinder 25 and the upper end of the temperature-sensitive case 10, thereby sealing.

  A second rod 28 is disposed in the outer casing 24. The second rod 28 constitutes an output rod and protrudes from a circular hole 29 in the upper part of the outer casing 24. The circular hole 29 is attached with a seal member 30 that also serves as a tapered guide. The upper end of the second rod 28 is guided by the seal member 30, and foreign matter is introduced through the second rod 28. Intrusion into the outer casing 24 is prevented. The seal member 30 is fixed by a spring receiver 31 coupled to the upper end of the outer casing 24. A spring receiver 33 is integrally provided at the lower end side of the second rod 28. A projecting portion 34 projecting in the outer peripheral direction is connected to the lower end of the spring receiver 33, and the projecting portion 24 is in sliding contact with the inner peripheral surface of the outer casing 24, thereby stabilizing the lower end portion of the second rod 28. Has come to be supported.

  A return spring 32 for pushing back the second rod 28 downward is housed in the outer casing 24. That is, the return spring 32 has an upper end received by a spring receiver 31 attached to the upper portion of the outer casing 24, and a lower end received by a protrusion 34 of a spring receiver 33 at the lower end of the second rod 28. The rod 28 is pressed downward.

  Next, a relief mechanism for absorbing the overstroke of the first rod 15 will be described. A compression coil spring 40 made of, for example, a wave spring is accommodated in the spring receiver 33 of the second rod 28. The lower end of the coil spring 40 is received by the spring receiver 41. The spring receiver 41 is received by a stopper ring 42 that is locked by a groove on the outer peripheral portion of the first rod 15. Accordingly, the first rod 15 is pressed downward by the compression coil spring 40 through the spring receiver 41 and the stopper ring 42. When a wave spring is used as the compression coil spring 40, a large elastic restoring force can be taken out with a small deformation.

  Next, the operation of the temperature sensitive actuator configured as described above will be described. The compression coil spring 40 housed in the spring receiver 33 of the second rod 28 is composed of a hard spring, and the elastic restoring force of the spring is the maximum shown in FIG. 3A by the return spring 32 that returns the second rod 28. The value is larger than the elastic restoring force when compressed to the stroke. Therefore, the compression coil spring 40 functions as a rigid body until the second rod 28 moves the maximum stroke.

  The temperature-sensitive wax 11 in the temperature-sensitive case 10 expands and contracts according to the temperature outside the temperature-sensitive case 10. As the temperature rises, the temperature-sensitive wax 11 in the temperature-sensitive case 10 expands, so that the spool 12 formed of an extruded tube is squeezed. The spool 12 expands as the temperature of the temperature-sensitive wax 11 increases. To extrude the first rod 15 as shown in FIG. 3A. At this time, since the elastic restoring force of the compression coil spring 40 is larger than the elastic restoring force of the second return spring 32 and functions as a rigid body, the output stroke of the first rod 15 is the compression coil spring 40. Is transmitted to the spring receiver 33 of the second rod 28, whereby the second rod 28 moves upward by the same stroke as the first rod 15. Therefore, there is no relative movement between the first rod 15 and the second rod 28 in this state.

  As shown in FIG. 3A, when the second rod 28 is pressed to the set stroke by the first rod 15, the spring receiver 31 in which the upper end of the spring receiver 33 of the second rod 28 is attached to the upper end of the outer casing 24. Abut. Accordingly, the second rod 28 cannot move upward any further. The value at this time corresponds to the set stroke.

  With the second rod 28 thus moved to the set stroke, which is the maximum stroke, the temperature outside the temperature sensitive case 10 further rises, and the temperature sensitive wax 11 squeezes the spool 12 to cause the first rod 15 to move. When extruded, the relief mechanism is now actuated as shown in FIG. 3B. The operation of the relief mechanism is performed by the deformation of the compression coil spring 40 accompanying the movement of the first rod 15, and relative to the second rod 28 of the first rod 15 accompanying the deformation of the compression coil spring 40. Achieved by moving.

  When the ambient temperature of the temperature sensitive case 10 rises to a temperature higher than the set stroke, the spool 12 further squeezes the first rod 15 by the expansion of the temperature sensitive wax 11. Then, the first rod 15 further moves upward while compressing the compression coil spring 40 in the spring receiver 33 of the second rod 28. That is, the first rod 15 rises while contracting the compression coil spring 40 via the stopper ring 42 and the spring receiver 41. At this time, since the upper end of the spring receiver 33 is in contact with the lower end of the spring receiver 31 as described above, the second rod 28 is maintained at the set stroke without any further stroke. Therefore, even if the ambient temperature rises above the temperature corresponding to the set stroke, the overstroke of the first rod 15 due to such temperature rise is compressed in the spring receiver 33 of the second rod 28. Absorbed by the relief mechanism comprising the coil spring 40, no further output stroke is generated.

  FIG. 4 shows such a change in the output stroke. Although the output stroke increases until the temperature outside the temperature sensing case 10 reaches the set temperature, the stroke of the actuator is increased when the temperature exceeds the set temperature. It remains constant at the set stroke. Therefore, an unexpected load is not given to an apparatus in which such an actuator is incorporated due to an overstroke. Alternatively, it is not necessary to provide a limiter mechanism for absorbing an overstroke by the actuator in a device to which the actuator is attached. A desired stroke can be appropriately expressed by the second rod 28 in accordance with the external temperature, and can be used as a temperature-sensitive actuator.

  The characteristic shown in FIG. 6 shows the stroke characteristic by a modification. Here, the spring constant of the compression coil spring 40 constituting the relief mechanism shown in FIG. 5 is set larger than the spring constant of the return spring 32, and the compression coil spring 40 constituting the relief mechanism is harder and the return spring. 32 is a softer spring. The return spring 32 is mounted between the spring receiver 31 and the protruding portion 34 of the spring receiver 33 in a state where a predetermined set pressure is applied in advance. On the other hand, the compression coil spring 40 in the spring receiver 33 is assembled with the set load being zero.

  Therefore, when the temperature outside the temperature sensing case 10 rises and the first rod 15 is pushed out, the compression coil spring 40 is compressed as shown in FIG. The stroke of the rod 15 is not transmitted to the second rod 28. When the elastic restoring force of the compression coil spring 40 exceeds the elastic restoring force of the return spring 32, the stroke of the first rod 15 is transmitted to the second rod 28 via the compression coil spring 40. . When the spring receiver 33 connected to the second rod 28 comes into contact with the upper spring receiver 31, the second rod 28 can no longer move upward, and thereafter the first rod 15 The compression coil spring 40 is compressed in accordance with the movement, and the deformation of the compression coil spring 40 absorbs the output of the first rod 15 to absorb the overstroke.

  The characteristics of the actuator having such a setting are the same as the characteristics shown in FIG. On the other hand, the initial characteristic is that the output of the rod of the second rod 28 is delayed by the absorption of the initial displacement of the first rod 15 by the relief mechanism comprising the compression coil spring 40, thereby causing FIG. As shown in FIG. 6, the change of the stroke with respect to the temperature in the initial stage becomes steep, and the response is improved. Therefore, an actuator suitable for increasing the sensitivity at a temperature below the set temperature is provided.

  Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention. For example, the set temperature and the set stroke in the above embodiment can be changed to various values according to the requirements of the equipment used.

  The present invention can be used as a temperature-sensitive actuator that generates an appropriate stroke according to the ambient temperature or the external temperature.

It is a top view of a temperature-sensitive actuator. It is an AA longitudinal cross-sectional view in FIG. It is a longitudinal cross-sectional view which shows the state of a full stroke (A) and the overstroke (B). It is a graph which shows the change of the output stroke with respect to temperature. It is a longitudinal cross-sectional view of the actuator of a modification. It is a graph which shows the change of output stroke with respect to the temperature of the actuator of a modification.

Explanation of symbols

10 Temperature Sensitive Case 11 Temperature Sensitive Wax 12 Spool (Extruded Tube)
DESCRIPTION OF SYMBOLS 13 Guide 14 Insertion hole 15 1st rod 16-18 O-ring 24 Outer casing 25 Connecting cylinder 26 Spacer 27 O-ring 28 Second rod 29 Circular hole 30 Seal member 31 Spring receiver 32 Return spring 33 Spring receiver 34 Protrusion 40 Compression coil spring 41 Spring receiver 42 Stopper ring

Claims (6)

An extruded tube is inserted into a temperature sensitive case filled with the temperature sensitive substance, and the first rod having a base end inserted into the extruded tube is inserted into the temperature sensitive substance with the temperature change outside the temperature sensitive case. In the temperature-sensitive actuator that extrudes in response to expansion and contraction,
In addition to having a second rod that generates an output stroke in conjunction with the pushing operation of the first rod, a relief mechanism is provided between the first rod and the second rod, and the second rod A temperature-sensitive actuator, wherein when the first rod is further pushed out after moving a set stroke, the stroke of the first rod is absorbed by the relief mechanism.   The temperature-sensitive actuator according to claim 1, wherein the temperature-sensitive substance is a temperature-sensitive wax.   The extruded tube is a flexible cylindrical bag with a closed end, and the closed end of the tube is inserted into a temperature sensitive case, and the first rod is opened from the opened proximal end side. The temperature-sensitive actuator according to claim 1, wherein is inserted into the tube.   The relief mechanism is a compression coil spring interposed between the first rod and the second rod, and the elastic restoring force of the compression coil spring is obtained when the second rod moves a set stroke. 2. The compression coil spring functions as a rigid body while being set larger than an elastic restoring force of a return spring of the second rod, and the second rod moves to a set stroke. Temperature-sensitive actuator.   The relief mechanism is a compression coil spring interposed between the first rod and the second rod, and the spring constant of the compression coil spring is larger than the spring constant of the return spring of the second rod. When the set load of the return spring is set to be larger than the set load of the compression coil spring constituting the relief mechanism and the first rod is pushed out, the compression coil spring constituting the relief mechanism first. When the elastic restoring force of the compression coil spring exceeds the elastic restoring force of the return spring, the stroke of the first rod is transmitted to the second rod through the compression coil spring. The temperature-sensitive actuator according to claim 1.   The second rod is movably disposed in a cylindrical outer casing, and the relief is provided between a spring receiver on the proximal end side of the second rod and a spring receiver on the distal end side of the first rod. The compression coil spring which comprises a mechanism is interposed, The output stroke of the said 1st rod is transmitted to the said 2nd rod via the said compression coil spring, The Claim 4 or Claim 5 characterized by the above-mentioned. Temperature-sensitive actuator.

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