JP2009168172A - Bellows - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform smooth operation of a bellows in association with the movement of a movable member. <P>SOLUTION: This bellows includes a first fixed portion 29 formed at one end, a second fixed portion 33 formed at the other end, and a body portion 47 provided between the first and second fixed portions 29, 33 and formed into a hollow cylindrical shape with its diameter gradually reduced from one end to the other end. The first fixed portion 29 is fixed to a stationary side 47, and the second fixed portion 33 is fixed to the movable member 17 linearly advanced and retreated with respect to the stationary side 47. When the second fixed portion 33 is moved to the side of the first fixed portion 29 side by the movement of the movable member 17, a first bent portion 75 projecting to the side of the second fixed portion 33 is formed nearer the first fixed portion 29 side of the body portion 47, and also a second bent portion 77 projecting to a side opposite to the first bent portion 75 is reversely formed between the first bent portion 75 and the second fixed portion 33. The second bent portion 77 is movable in the moving direction of the movable member in an inversion condition in association with the forward and backward movement of the movable member 17. The thickness of the body portion 47 is gradually increased toward the first fixed portion 29 side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bellows that covers a movable member that can linearly advance and retreat, such as a push rod of an actuator.

  In recent refrigerators, the doors for opening and closing the refrigerator compartment and the like are also enlarged with the increase in size. In such a large-sized refrigerator door, the adsorption force for maintaining the closed state is increased, and as a result, the operation force for opening is also increased. For this reason, some refrigerators cause the door to be opened by an actuator.

  Such an actuator includes a push rod as a movable member that can move forward and backward with respect to the main body, and pushes the door from the inside when the push rod advances. When such an actuator is installed in the refrigerator compartment, when the door is opened, outside air may enter into the main body from between the push rods, which may cause malfunction of the actuator due to condensation or freezing (for example, , See Patent Document 1).

  For this reason, when installing in a refrigerator compartment, it is possible to block | close outside air etc. by accommodating an actuator in a sealed state in a storage case. In this case, the push rod is covered with a flexible hollow cylindrical bellows. The bellows allows the push rod to move back and forth while forming a protruding bent portion in the moving direction.

  However, if the bellows having the conventional structure is applied as it is, the shape of the bent portion is broken due to repeated forward and backward movement of the push rod, and smooth operation cannot be performed.

Japanese Patent Laid-Open No. 5-141853

  The problem to be solved is that the bellows cannot be smoothly operated as the movable member moves.

  In the present invention, in order to enable a smooth operation of the bellows accompanying the movement of the movable member, a circular first fixing portion is formed at one end and a circular second fixing portion is formed at the other end. The main body between the first and second fixing parts is formed in a hollow cylindrical shape whose diameter gradually decreases from one end side to the other end side, and the first fixing part is fixed to the stationary side and the second fixing When the second fixed portion moves toward the first fixed portion by the movement of the movable member, the first portion of the main body portion is fixed to the movable member that linearly moves forward and backward relative to the stationary side. A first bent portion projecting toward the second fixed portion is formed near the fixed portion, and opposite to the first bent portion between the first bent portion and the second fixed portion. The second bent portion of the protrusion is formed in an inverted manner, and the second bent portion moves in accordance with the advance / retreat movement of the movable member. The body portion is formed so that the thickness of the main body portion gradually becomes thicker relative to the second fixed portion side toward the first fixed portion side. This is the main feature.

  In the bellows of the present invention, since the main body portion gradually becomes smaller in diameter toward the second fixed portion side, when the second fixed portion moves toward the first fixed portion side due to the movement of the movable member, A first bent portion that protrudes toward the second fixed portion from the fixed portion can be formed, and between the first bent portion and the second fixed portion, to the opposite side with respect to the first bent portion. The second bent portion of the protrusion can be inverted.

  Then, the second bent portion moves with the movable member moving forward and backward while maintaining the inverted state in the moving direction, and allows the movable member to move.

  And since the thickness of the main body portion is gradually increased toward the first fixed portion side, the rigidity of the first fixed portion side having a large diameter is improved, and the first bent portion The bent shape can be reliably maintained.

  Moreover, the second bent portion can maintain the bent shape reliably by suppressing the change in rigidity even after moving with the movement of the movable member due to the gradually thicker shape of the main body portion.

  Therefore, the operation accompanying the movement of the movable member can be smoothly performed while maintaining the first and second bent portions.

  The object of enabling smooth operation of the bellows accompanying the movement of the movable member is realized by gradually increasing the thickness of the main body.

1 is a schematic cross-sectional view showing an actuator unit to which a bellows according to a first embodiment of the present invention is applied, and is attached in a refrigerator. FIG. 2 is an enlarged cross-sectional view of a main part of FIG.
[Configuration of actuator unit]
As shown in FIG. 1, the actuator unit 1 according to the present embodiment is installed in the refrigerator compartment 5 of the refrigerator 3 and is used as a door opening device that opens the door 7 of the refrigerator compartment 5. The actuator unit 1 is fixed to the inner surface that defines the refrigerator compartment 5, for example, the upper surface of the refrigerator compartment 5. However, it is also possible to fix to the side surface or the lower surface of the refrigerator compartment 5. The actuator unit 1 according to the present embodiment is applied to the opening of the pull-out door 7, but can also be applied to the opening of the rotary door.

  The actuator unit 1 houses an electromagnetic solenoid 9 as an actuator in a sealed state in a housing case 13 having a bellows 11.

  As shown in FIGS. 1 and 2, the electromagnetic solenoid 9 includes a main body 15 and a push rod 17 as a movable member provided on the main body 15. The push rod 17 is supported so as to be able to advance and retreat linearly along the axial direction with respect to the main body 15. The push rod 17 advances with respect to the main body 15 when the main body 15 is energized by the operation of a switch provided on a handle portion (not shown) of the door 7. An annular convex portion 19 is formed in a circular shape on the outer periphery of the tip of the push rod 17.

  The electromagnetic solenoid 9 has a main body 15 fixed in the refrigerating chamber 5 via a storage case 13 described later, and a push rod 17 is arranged along the direction in which the door 7 is pulled out. A pressing member 21 is interposed between the push rod 17 and the inner surface of the door 7.

  The housing case 13 includes a case portion 23 fixed to the upper surface of the refrigerator 3 and a bellows 11 attached to the case portion 23.

  The case portion 23 is made of synthetic resin or the like and includes a base portion 25. The base portion 25 is closed by a lid (not shown) and accommodates and supports the main body 15 of the electromagnetic solenoid 9. The case portion 23 is provided with an opening 27 for inserting the push rod. A fitting groove 31 for fixing a first fixing portion 29 of the bellows 11 described later is formed on the inner peripheral surface of the opening 27 in a circular shape.

  The bellows 11 is formed in a flexible hollow cylindrical shape, the first fixing portion 29 at one end is fixed to the opening 27 of the case portion 23 and the other end is a push rod of the electromagnetic solenoid 9. 17 is fixed to the tip. As a result, the bellows 11 covers the push rod 17 of the electromagnetic solenoid 9 while allowing the forward / backward movement, and closes the opening 27 of the case portion 23.

In such an actuator unit 1, the door 7 of the refrigerator 3 can be pushed open by the advancement of the push rod 17 of the electromagnetic solenoid 9 while preventing the outside air and cold air from entering the inside.
[Specific structure of bellows]
3 is a cross-sectional view showing a bellows before assembly applied to the actuator unit of FIG. 1, and FIG. 4 is a side view thereof.

  The bellows 11 is made of a flexible elastic material such as silicon rubber, and is formed so as to gradually become smaller in diameter from one end side to the other end side as shown in FIGS. A first fixing portion 29 is formed at one end of the bellows 11, and a second fixing portion 33 is formed at the other end. The bellows 11 has a basic thickness of 0.3 mm to 0.6 mm when the maximum diameter is 30 mm.

  The first fixing portion 29 includes a cylindrical portion 35 at one end and an annular protrusion 37 formed in a circular shape on the outer periphery of the cylindrical portion 35. The cylindrical portion 35 is formed so as to gradually increase in diameter toward the annular protrusion 37 according to the taper shape of the deformable portion 51 described later. A tapered surface 39 is formed on the inner peripheral side of the cylindrical portion 35. The second fixing portion 33 includes a cylindrical portion 41 at the other end and an annular recess 43 formed in a circular shape on the inner periphery of the cylindrical portion 41. A through hole 45 is formed at the tip of the cylinder portion 41 of the second fixing portion 33. The wall portions 35 and 41 are thicker than the main body portion 47 between the first and second fixing portions 33.

  The main body 47 includes an undeformed portion 49 on the second fixing portion 33 side and a deforming portion 51 on the first fixing portion 29 side. The non-deformable portion 49 extends from the second fixing portion 33 to the intermediate portion. The non-deformable portion 49 is formed with a small diameter having a substantially constant cross section along the push rod 17 of the electromagnetic solenoid 9. In the present embodiment, the non-deformable portion 49 is formed to have a slightly larger diameter toward the intermediate portion. The non-deformable portion 49 is thicker than the later-described deformable portion 51 and is set so as not to be deformed as the push rod 17 of the electromagnetic solenoid 9 moves.

  The deformation part 51 extends from the non-deformation part 49 to the first fixing part 29. The deformation portion 51 has a tapered shape such that the small diameter portion 53 is continuous with the non-deformation portion 49 and gradually increases in diameter toward the large diameter portion 55 continuous with the cylindrical portion 35 of the first fixing portion 29 of the bellows 11. Is formed. The taper shape of the deformable portion 51 is set so that contact between the main body portions 47 does not occur when the bellows 11 is operated. Specifically, the taper angle α is set to 20 ° or more, preferably 30 ° or more.

  The thickness of the deformed portion 51 gradually increases from the small diameter portion 53 toward the large diameter portion 55. In this embodiment, the change rate of the thickness from the small diameter portion 53 to the large diameter portion 55 is 10% to 20%. The wall thickness is appropriately set in a relative relationship with the tapered shape so as to ensure the flexibility on the small diameter portion 53 side while ensuring the rigidity on the large diameter portion 55 side.

  The deformable portion 51 is provided with an easily deformable portion 56 adjacent to the first fixing portion 29. The easily deformable portion 56 includes a curved portion that protrudes toward the inner diameter side of a hollow cylinder. The curvature of the easily deformable portion 56 is set according to the thickness and taper angle of the deformable portion 51. In the present embodiment, the curvature is set so as to be recessed toward the inner diameter side by about 0.5 mm to 0.7 mm at the maximum with respect to the deformed portion 51.

  The bellows 11 having such a configuration is fixed to the case portion 23 in a state where the first fixing portion 29 is held by the holder 57 as shown in FIGS. 1 and 2.

  The holder 57 includes an outer member 59 and an inner member 61 that is locked to the outer member 59. The outer member 59 is made of a synthetic resin or the like and is formed in an annular shape. On one side of the inner peripheral surface of the outer member 59, a flange portion 63 for abutting the annular protrusion 37 of the first fixing portion 29 is provided in a circular shape. A cylindrical guide wall 65 is provided on the inner peripheral edge of the flange portion 63. The guide wall 65 is formed in a tapered shape and is along the tapered surface 39 of the first fixing portion 29. The guide wall 65 can guide the annular protrusion 37 of the first fixing portion 29 against the flange portion 63 of the outer member 59, and can be easily assembled. On the other side of the inner peripheral surface of the outer member 59, a circular locking claw 67 is provided.

  The inner member 61 is made of a synthetic resin or the like and is formed in an annular shape. The inner member 61 has a tapered shape corresponding to the tapered shape of the deformed portion 51 of the bellows 11, and sandwiches the cylindrical portion 35 of the first fixed portion 29 with the guide wall 65 of the outer member 59. A flange portion 69 is formed in a circular shape on one outer periphery of the inner member 61. The flange portion 69 engages with the locking claw 67 of the outer member 59 and holds the annular protrusion 37 of the first fixing portion 29 between the flange portion 69 and the flange portion 63 of the outer member 59.

In the holder 57, the annular protrusion 37 of the first fixing portion 29 is abutted against the flange portion 63 of the outer member 59, and the inner member 61 is against the outer member 59 of the flange portion 69 to the locking claw 67. Lock by engagement. Thereby, the first fixing portion 29 of the bellows 11 is held by the holder.
In this way, the holding tool 57 is fitted into the fitting groove 31 of the case portion 23 while the first fixing portion 29 is held. A seal member (not shown) is disposed between the holder 57 and the fitting groove 31.

The second fixing portion 33 is fixed to the distal end of the push rod 17 with the annular concave portion 43 closely fitting to the annular convex portion 19 at the distal end of the push rod 17 of the electromagnetic solenoid 9.
[Operation of bellows]
Hereinafter, the operation of the bellows will be described with reference to FIGS. In FIG. 2, the upper side of the center line C shows the advanced state of the push rod 17 of the electromagnetic solenoid 9, and the lower side of the center line C shows the retracted state of the push rod 17.

  Immediately after assembling the bellows 11 to the actuator unit 1, the bellows 11 is fully extended as shown in FIG. Therefore, the bellows 11 is first deformed from the extended state to the retracted state of FIG.

  The deformation to the retracted state is performed by moving the second fixing portion 33 toward the first fixing portion 29 as the push rod 17 of the electromagnetic solenoid 9 retracts to the retracted position.

  By the movement, a compressive force acts on the bellows 11, and stress concentrates on the easily deformable portion 56 of the curved deformable portion 51 to start deformation. In the deformation of the easily deformable portion 56, the easily deformable portion is arranged so that the small diameter end portion 71 which is the second fixed portion 33 side end portion is close to the large diameter end portion 73 side which is the first fixed portion 29 side end portion. 56 is expanded toward the inner diameter side while being compressed. As a result, the easily deformable portion 56 is deformed so that the small diameter end portion 71 is inserted into the large diameter end portion 73.

  As the deformation progresses, the easily deformable portion 56 reverses and shifts to a protruding bent shape toward the second fixed portion 33, and the first bent from the first fixed portion 29 of the main body portion 47. Part 75 is formed. On the other hand, between the first bent portion 75 and the second fixed portion 33 of the deformable portion 51, a second bent portion 77 projecting in the opposite direction with respect to the first bent portion 75 is inverted. .

  Thus, in the bellows 11, the first and second fixing portions 29 and 33 can be formed due to the easily deformable portion 56 of the deformable portion 51.

  Since the first bent portion 75 formed in this way is gradually thickened from the small diameter portion 53 side of the deformable portion 51, the rigidity can be improved. That is, it is possible to compensate for a decrease in rigidity accompanying a change in diameter due to the tapered shape of the deformable portion 51 by increasing the thickness. For this reason, the 1st bending part 75 can maintain the bending shape reliably. In addition, since the first bent portion 75 is in a state in which the curved shape of the easily deformable portion 56 is reversed, a force for returning to the state before the deformation acts, and the bent shape can be more reliably maintained. .

  On the other hand, after the formation, the second bent portion 77 moves in the retracting direction in accordance with the retracting movement of the push rod 17 of the electromagnetic solenoid 9, and the formation position is shifted to the small diameter portion side of the deformable portion 51. Here, the deformation | transformation part 51 is suppressing the rigid change by a taper shape as mentioned above. Therefore, the second bent portion 77 can reliably maintain the bent shape by suppressing the change in rigidity during and after the movement in the retracting direction accompanying the movement of the push rod 17.

  Next, when the door 7 of the refrigerator 3 is opened, the bellows 11 is deformed from the retracted state to the advanced state with the advancement of the push rod 17 of the electromagnetic solenoid 9.

  The deformation to the advanced state is performed by moving the second fixing portion 33 toward the first fixed portion 29 side as the push rod 17 of the electromagnetic solenoid 9 advances to the advanced position.

  At this time, a tensile force acts on the bellows 11 as a whole, the second bent portion 77 moves in the advancing direction of the push rod 17, and its formation position transitions to the large diameter portion 55 side of the deformable portion 51.

  As described above, the second bent portion 77 has a gradually thicker shape, so that a change in rigidity during and after the movement is suppressed, and the bent shape can be reliably maintained.

  On the other hand, the first bent portion 75 can also reliably maintain the bent shape by suppressing the decrease in rigidity due to the gradually thicker shape and reversing the curved shape of the easily deformable portion 56 as described above.

After the door 7 is opened, the bellows 11 is deformed from the advanced state to the retracted state as the push rod 17 of the electromagnetic solenoid 9 is retracted, but this is performed in the same manner as the deformation from the extended state.
[Effect of Example]
In the bellows 11 of the present embodiment, the deformed portion 51 of the main body portion 47 has a tapered shape that gradually increases in diameter toward the first fixed portion 29 side, and thus the second movement is caused by the movement of the push rod 17 of the electromagnetic solenoid 9. When the fixing portion 33 moves to the first fixing portion 29 side, a first bent portion 75 that protrudes toward the second fixing portion 33 side can be formed from the first fixing portion 29 and the first fixing portion 29 can be formed. It is possible to reversely form the second bent portion 77 projecting to the opposite side with respect to the first bent portion 75 between the bent portion 75 and the second fixed portion 33.

  As the push rod 17 moves forward and backward, the second bent portion 77 moves while maintaining the inverted state in the moving direction, and allows the push rod 17 to move.

  At this time, since the thickness of the deformable portion 51 gradually increases toward the first fixed portion 29, the rigidity of the first fixed portion 29 having a large diameter can be improved. . Therefore, the 1st bending part 75 can maintain a bending shape reliably.

  Moreover, since the thickness of the deformed portion 51 gradually increases toward the first fixed portion 29, the second bent portion 77 changes in rigidity even after moving with the movement of the push rod 17. And the bent shape can be reliably maintained.

  Therefore, in the bellows 11 of the present embodiment, even if the push rod 17 of the electromagnetic solenoid 9 is repeatedly moved back and forth, the operation accompanying the movement of the push rod 17 while maintaining the first and second bent portions 77. Can be performed smoothly, and durability can also be improved.

Moreover, in the bellows 11, since the 1st, 2nd bending part 77 can be maintained reliably, even if the stroke amount l of the push rod 17 increases, operation | movement can be performed smoothly.
Since the easily deformable portion 56 is provided adjacent to the first fixing portion 29 of the deformable portion 51 and causes the formation of the first and second bent portions 75 and 77, the deformable portion 51 is gradually thickened. Even if it exists, it can deform | transform easily and reliably and can form the 1st, 2nd bending part 75,77.

Since the easily deformable portion 56 is formed in a curved shape that protrudes toward the inner diameter side, stress is likely to concentrate, which can be attributed to forming the first and second bent portions 75 and 77 more easily and reliably. . In addition, in the bellows 11, the easily deformable portion 56 adjacent to the first fixed portion 29 is inverted to form the first bent portion 75, so that the bent shape can be maintained more reliably.
[Others]
The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the present embodiment, the bellows 11 is applied to the actuator unit 1 that opens the door 7 of the refrigerator 3. However, the bellows 11 can also be applied to a damper unit for buffering when the door 7 is closed.

  Moreover, although the bellows 11 is being fixed to the case part 23 of the storage case 13 via the holder 57, the holder 57 can also be abbreviate | omitted. In this case, it is preferable to employ the structure of the holder on the case portion side.

  In the bellows 11 of the above embodiment, the deformed portion 51 is formed in a tapered shape with respect to the non-deformed portion 49 having a substantially constant cross section, but the taper without steps from the non-deformed portion to the deformed portion. It can also be formed into a shape.

  Moreover, although the bellows 11 is provided with the easily deformable part 56, the easily deformable part 56 is also omissible.

  Further, the easily deformable portion 56 is formed in a curved shape that protrudes toward the inner diameter side, but is not limited to the curved shape, and may be a cause of deformation of the deformable portion 51.

(Example 1) which shows the actuator unit which applied the bellows, and is the schematic sectional drawing of the state attached in the refrigerator. FIG. 2 is a cross-sectional view showing the main part of the actuator unit of FIG. 1, showing the push rod advance and retreat state above and below the center line C (Example 1). (Example 1) which is sectional drawing which shows the bellows applied to the actuator unit of FIG. (Example 1) which is a side view which shows the bellows applied to the actuator unit of FIG.

Explanation of symbols

11 Bellows 13 Storage case (stationary side)
17 Push rod (movable member)
29 First fixing portion 33 Second fixing portion 47 Main body portion 49 Non-deformable portion 51 Deforming portion 53 Small diameter portion 55 Large diameter portion 56 Easy deformable portion 75 First bent portion 77 Second bent portion

Claims (5)

A circular first fixing portion is formed at one end and a circular second fixing portion is formed at the other end, and the main body between the first and second fixing portions is moved from one end side to the other end side. It is formed in a hollow cylindrical shape with a gradually decreasing diameter,
The first fixed portion is fixed to a stationary side, and the second fixed portion is fixed to a movable member that linearly moves back and forth with respect to the stationary side;
When the second fixed portion moves toward the first fixed portion due to the movement of the movable member, a first bent portion projecting toward the second fixed portion is closer to the first fixed portion of the main body portion. A second bent portion projecting to the opposite side of the first bent portion is inverted between the first bent portion and the second fixed portion,
The second bent portion is a bellows that is movable in an inverted state in the moving direction as the movable member moves forward and backward,
The thickness of the main body is formed so as to be gradually thicker relative to the second fixed portion side toward the first fixed portion side.
Bellows characterized by that. The bellows according to claim 1,
Provided near the first fixed portion of the main body portion is an easily deformable portion that causes the formation of the first and second bent portions.
Bellows characterized by that. The bellows according to claim 2,
The easily deformable portion is a curved portion protruding toward the inner diameter side of a hollow cylinder.
Bellows characterized by that. The bellows according to any one of claims 1 to 3,
The main body portion includes a small-diameter non-deformable portion on the second fixed portion side, and a deformable portion that continues to the non-deformable portion and reaches the large-diameter portion on the first fixed portion side,
The thickness of the deformed portion was formed so as to gradually increase from the small diameter portion toward the large diameter portion,
Bellows characterized by that. The bellows according to claim 1, wherein
The movable member is an actuator push rod,
The actuator body is housed and supported in a case portion having an opening through which the push rod is inserted,
Fixing the first fixing part to the opening of the case part and closing the case part;
Bellows characterized by that.

Images