Door hinge structure

Abstract

In a door hinge structure that assists the movement of a door, this invention prevents noise caused by the clearance between the hinge pin and the insertion hole of the lower spacer over a long period of time. [Solution] The first cam portion 23 is composed of three lower protrusions 42, downward-sloping portions 43 on both sides of each lower protrusion 42, and a lower recess 44 formed between adjacent lower slope portions 43. An insertion hole 41 through which a hinge pin 21 is inserted with clearance is provided, surrounded by these lower protrusions 42, downward slope portions 43, and lower recesses 44. A slit 60 opening toward the insertion hole 41 is formed in each lower recess 44, and a cantilevered elastic arm 61 that can be elastically deformed in the radial direction of the hinge pin 21 is formed between the slit 60 and the insertion hole 41. A restricting body 62 is provided projecting from each elastic arm 61 toward the center of the insertion hole 41, and the restricting body 62 is brought into contact with the circumferential surface of the hinge pin 21.

Description

Technical Field

[0001] The present invention relates to a door hinge structure that swingably supports a door for opening and closing an opening of a storage device such as a refrigerator or a freezer.

Background Art

[0002] The door hinge structure according to the present invention includes a biasing action for automatically opening and closing the door, a closing action for supporting the door in a fully closed position, and an opening action for supporting the door in a fully open position. A door hinge structure having the same actions is known from Patent Document 1. In the door hinge structure of Patent Document 1, a hinge plate on the main body side having a hinge pin projecting upward, a lower spacer (pin-side collar) fixed to the hinge plate with the hinge pin inserted through an insertion hole, and an upper spacer (hole-side collar) fixed to the door with the hinge pin inserted through an insertion hole (bearing hole) constitute a lower hinge mechanism (lower-side hinge mechanism). Around the insertion hole of the lower spacer, three lower convex portions (convex portions) of a first cam portion project upward, and around the insertion hole of the upper spacer, three upper convex portions (convex portions) of a second cam portion project downward. The upper spacer and the lower spacer are arranged vertically so that both cam portions mesh with each other. On both sides of the flat surface of each convex portion, an inclined portion having an inclined surface is provided, and the inclined portions of these cam portions contact each other, and the upper inclined portion (inclined portion) of the second cam portion slides down the lower inclined portion (inclined portion) of the first cam portion to exhibit each of the above actions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of door hinge structure, the upper and lower spacers are molded from resin using a mold molding method, and the hinge plate is molded from stainless steel using lost-wax casting. However, compared to the mold molding method, which allows for relatively high-precision molding, it is difficult to accurately form the diameter dimensions of the hinge pin through which the upper and lower spacers are inserted using lost-wax casting. Therefore, in Patent Document 1, the diameter dimensions of the insertion holes for the upper and lower spacers are molded to be slightly larger than the design dimensions of the hinge pin, thereby intentionally creating a clearance between the hinge pin and the insertion holes of each spacer. This allows both spacers to be assembled to the hinge pin without being affected by the molding precision of the hinge pin.

[0005] As described above, if there is clearance between the hinge pin and the insertion holes of each spacer, especially between the hinge pin and the insertion hole of the lower spacer, the lower spacer can be displaced relative to the hinge plate by the amount of the clearance. Therefore, when the assisting action of the door begins, the lower spacer moves and impacts the hinge pin, causing a noise. Specifically, when the door is opened to an intermediate position between fully closed and fully open, with the flat surfaces of the convex parts of both cams in contact, and the door is then closed, the flat surface of the second cam passes over the flat surface of the first cam, at which point the inclined parts of both cams come into contact and the assisting action in the closing direction begins. At this time, the reaction force of the assisting force (rotational moment) acting around the hinge pin is transmitted to the first cam via the second cam and acts on the lower spacer as a rotational moment in the opposite direction to the assisting force. The lower spacer has room to displace relative to the hinge pin by the amount of clearance, so the reaction force of the assisting force causes the lower spacer to move on the hinge plate, and the inner surface of the insertion hole strikes the hinge pin, producing a sound. This is the same when the door is opened from an intermediate position.

[0006] To prevent such noise, the door hinge structure of Patent Document 1 has two anti-rattle protrusions projecting toward the center of the insertion hole of the lower spacer from the inner circumferential surface of the insertion hole. By bringing these two anti-rattle protrusions and the inner circumferential surface of the insertion hole into contact with the hinge pin at three points, the displacement of the lower spacer caused by clearance is restricted, thereby preventing noise. However, in the case of a lower spacer made of resin, it is unavoidable that the anti-rattle protrusions will gradually be crushed and deformed by the repeated reaction force. When the lower spacer becomes displaceable due to the deformation of the anti-rattle protrusions, the lower spacer will move due to the reaction force, causing noise.

[0007] The object of the present invention is to provide a door hinge structure that can prevent noise from occurring over a long period of time due to the clearance between the hinge pin and the insertion hole of the lower spacer, in a door hinge structure that assists the opening of a door. [Means for solving the problem]

[0008] The present invention relates to a door hinge structure comprising: a hinge plate 22 having an upwardly projecting hinge pin 21 and attached to the lower end of the side edge of the opening 12 of the storage compartment 1; a lower spacer 24 having a first cam portion 23 that is attached to the hinge plate 22 and fixed in a state where it is inserted through the hinge pin 21; and an upper spacer 26 having a second cam portion 25 that is fixed to the lower end of the side edge of the door 13 that opens and closes the opening 12 of the storage compartment 1 and engages with the first cam portion 23 when it is inserted through the hinge pin 21. The first cam portion 23 is formed at equiangled positions from the center of rotation and consists of three lower protrusions 42 having flat surfaces, lower inclined portions 43 having downward-sloping surfaces on both sides of each lower protrusion 42, and a lower recess 44 having a flat surface formed between adjacent lower inclined portions 43. An insertion hole 41 through which a hinge pin 21 is inserted with clearance is provided, surrounded by these lower protrusions 42, lower inclined portions 43, and lower recesses 44. A slit 60 opening toward the insertion hole 41 is formed in each lower recess 44, and a cantilevered elastic arm 61 that is elastically deformable in the radial direction of the hinge pin 21 is formed between the slit 60 and the insertion hole 41. A restricting body 62 is provided projecting from each elastic arm 61 toward the center of the insertion hole 41, and the restricting body 62 is in contact with the circumferential surface of the hinge pin 21.

[0009] The regulating body 62 is pressed toward the circumferential surface of the hinge pin 21 by the elastic restoring force of the elastic arm 61.

[0010] The diameter of the hinge pin 21 is defined as D1, the diameter of the insertion hole 41 as D2, and the diameter of the circle inscribed in the restricting body 62 when the lower spacer 24 is separated from the hinge plate 22 as D3. The diameter D2 is set to be larger than the diameter D1, and the diameter D3 is set to be smaller than the diameter D1.

[0011] The restrictor 62 is provided at the tip of the elastic arm 61 on the side of the insertion hole 41.

[0012] The lower spacer 24 comprises a spacer body 38 formed in a flat plate shape extending outward from the first cam portion 23, and a pair of lock arms 39-39 extending downward from the tip of the spacer body 38 in the direction of extension, for preventing detachment and rotation. The hinge plate 22 comprises a support plate 31 attached to the lower end of the side edge of the opening 12 of the storage compartment 1, and the support plate 31 is provided with a lock hole 35 that penetrates vertically, into which the lock arms 39 engage. The pair of lock arms 39-39 are arranged side by side with a virtual axis L defined by the extension direction of the spacer body 38 passing through the center of the hinge pin 21 in between. Each lock arm 39 comprises an arm portion 46 formed to be elastically deformable in directions toward and toward each other, and a claw portion 47 that protrudes from the lower end of the arm portion 46 in opposite directions and engages with the lower edge of the lock hole 35. The pair of arm portions 46-46 are engaged with the lock hole 35 in a state in which they are elastically deformed toward each other.

[0013] The lower spacer 24 is equipped with a positioning lock block 40 that protrudes downward from the lower surface of the spacer body 38. The support plate 31 has a recessed lock recess 34, which is a polygonal recess having two sides parallel to the virtual axis L in a plan view, allowing the insertion of the lock block 40. The lock block 40 is received by the vertical recess walls 34a·34a continuous with the two parallel sides, thereby restricting the rotation of the lower spacer 24 around the hinge pin 21. The lock block 40 is formed in a trapezoidal block shape with its upper and lower bases arranged perpendicular to the virtual axis L in a plan view. [Effects of the Invention]

[0014] In the door hinge structure according to the present invention, a slit 60 opening toward the insertion hole 41 is formed in each lower recess 44 constituting the first cam portion 23, and a cantilevered elastic arm 61 that is elastically deformable in the radial direction of the hinge pin 21 is formed between the slit 60 and the insertion hole 41. A restricting body 62 is provided projecting from each elastic arm 61 toward the center of the insertion hole 41, and the restricting body 62 is in contact with the circumferential surface of the hinge pin 21. In this way, even if there is a clearance between the hinge pin 21 and the insertion hole 41, the lower spacer 24 can be positioned with respect to the hinge pin 21 by the restricting body 62, thereby restricting the displacement of the lower spacer 24. By restricting the displacement of the lower spacer 24 with the restricting body 62 in this manner, it is possible to prevent the inner circumferential surface of the insertion hole 41 from impacting the hinge pin 21 due to the reaction force of the assisting force, thereby preventing noise from being generated by such impact. Furthermore, if a restrictor 62 is provided on the elastic arm 61 which is elastically deformable in the radial direction, even if the reaction force of the assisting force of the door 13 acts on the lower spacer 24, the elastic arm 61 elastically deforms in the radial direction of the hinge pin 21, thereby buffering the reaction force and preventing the restrictor 62 from being crushed and damaged. As described above, according to the door hinge structure of the present invention, the displacement of the lower spacer 24 is prevented by the restrictor 62, and furthermore, the restriction body 62 is prevented from being damaged by the elastic arm 61, so that noise caused by the clearance between the hinge pin 21 and the insertion hole 41 of the lower spacer 24 can be prevented over a long period of time.

[0015] When the regulating body 62 is pressed toward the circumferential surface of the hinge pin 21 by the elastic restoring force of the elastic arm 61, even if the lower spacer 24 moves slightly due to the reaction force of the assisting force of the door 13, causing one or two elastic arms 61 to elastically deform radially outward from the hinge pin 21, the remaining elastic arm 61 elastically returns to its radially inward position, maintaining the contact state between the hinge pin 21 and the regulating body 62. This makes it possible to more reliably prevent noise from occurring.

[0016] If the diameter D2 of the insertion hole 41 is set to be larger than the diameter D1 of the hinge pin 21, and the diameter D3 of the circle inscribed in the regulating body 62 is set to be smaller than the diameter D1 of the hinge pin 21, then by simply inserting the hinge pin 21 through the insertion hole 41 and attaching the lower spacer 24 to the hinge plate 22, a clearance can be provided between the hinge pin 21 and the insertion hole 41, while the regulating body 62 can be pressed toward the circumferential surface of the hinge pin 21 by the elastic force of the elastic arm 61, thus enabling the construction of a door hinge structure in a simple manner.

[0017] If the restrictor 62 is provided on the tip of the elastic arm 61 on the side of the insertion hole 41, the tip of the arm is the part of the elastic arm 61 that has a relatively large amount of elastic deformation. Therefore, even if a large assisting reaction force acts on the elastic arm 61 via the restrictor 62, this reaction force can be reliably buffered.

[0018] A pair of locking arms 39, 39 for preventing detachment and rotation are arranged side by side with a virtual axis L defined by the extension direction of the spacer body 38 passing through the center of the hinge pin 21 in between. Each locking arm 39 has an arm portion 46 that is elastically deformable in directions toward and toward each other, and a claw portion 47 that protrudes from the lower end of the arm portion 46 in opposite directions and engages with the lower edge of the locking hole 35. When the pair of arm portions 46, 46 are engaged with the locking hole 35 in a state where they are elastically deformed toward each other, the elastic restoring force of the arm portion 46 can press each locking arm 39 against the inner surface of the locking hole 35, so that no clearance is formed between each locking arm 39 and the locking hole 35, and the lower spacer 24 does not rattle around the hinge pin 21.

[0019] When the lock block 40 is received by the vertical recess walls 34a, 34a of the lock recess 34 that are continuous with two sides parallel to the virtual axis L in a plan view, the rotation of the lower spacer 24 around the hinge pin 21 is restricted. Even if one of the lock arms 39 is damaged, the lock block 40 can prevent the rotation of the lower spacer 24 around the hinge pin 21, so the engagement state of the remaining lock arm 39 can be maintained. In addition, when the lock block 40 is formed in a trapezoidal block shape with the upper and lower bases disposed in a direction perpendicular to the virtual axis L in a plan view, the end of the upper base portion of the trapezoidal block can be brought into contact with the lock recess 34, and the contact area between the lock block 40 and the lock recess 34 can be reduced. Therefore, the noise caused by the impact of the lock block 40 on the lock recess 34 can be reduced.

Brief Description of the Drawings

[0020] [Figure 1] It is a plan view showing a lower hinge mechanism in a door hinge structure according to an embodiment of the present invention. [Figure 2] It is a front view showing a refrigerator to which the door hinge structure is applied. [Figure 3] It is a front view showing the door hinge structure. [Figure 4] It is an exploded perspective view of the lower hinge mechanism. [Figure 5] It is a plan view of the first cam portion. [Figure 6] It is a sectional view taken along line A-A in FIG. 1. [Figure 7] It is a sectional view taken along line B-B in FIG. 6. [Figure 8] It is a sectional view taken along line C-C in FIG. 6. [Figure 9] It is a sectional view taken along line D-D in FIG. 6. [Figure 10] It is a longitudinal sectional view showing the two cam portions developed, where (a) shows the meshing state when the door is in the fully closed state, (b) shows the meshing state when the door is in the middle of opening and closing, and (c) shows the meshing state when the door is in the fully open state.

Mode for Carrying Out the Invention

[0021] (Embodiment) Figures 1 to 10 show an embodiment in which the door hinge structure according to the present invention is applied to a refrigerator. In this embodiment, front, back, left, right, and up and down refer to the intersecting arrows shown in Figures 1 to 4 and the front, back, left, right, and up and down indications written near each arrow. As shown in Figure 2, the refrigerator (storage unit) 1 is equipped with a main body case 4 made of an insulated box body that has two storage compartments 2 and 3, one above the other, in which raw ingredients and cooked food are stored. The space between the upper and lower storage compartments 2 and 3 is divided by a horizontal intermediate frame 5 that spans the upper and lower center of the front of the main body case 4.

[0022] The cooling system responsible for cooling storage chambers 2 and 3 consists of a condensing unit 6, which comprises a compressor, condenser, condenser fan, etc., and an evaporator 7. The condensing unit 6 is installed in a machine room 8 defined on the upper side of the main case 4, and the evaporator 7 is installed on the top surface of the upper storage chamber 2. The upper and lower storage chambers 2 and 3 are connected at the rear side of the intermediate frame 5, and by driving the evaporator fan 9 located below the evaporator 7, the air cooled by the evaporator 7 is circulated to cool the upper and lower storage chambers 2 and 3.

[0023] Doors 13 are provided at the entrances (openings) 12 formed on the front of each storage room 2 and 3, and these doors 13 allow each entrance 12 of the storage rooms 2 and 3 to be opened and closed. As shown in Figure 3, each door 13 is supported so as to be able to swing in the front-rear direction between a fully closed position (lower door 13 in Figure 2) and a fully open position (upper door 13 in Figure 2) by a door hinge structure consisting of an upper hinge mechanism 14 provided at the upper end of the right edge and a lower hinge mechanism 15 provided at the lower end of the right edge. In the fully open position, the swing of the door 13 in the opening direction is restricted by a stopper (not shown), and it is configured so that the door 13 swings 100° from the fully closed position to the fully open position.

[0024] The upper hinge mechanism 14 of the door hinge structure consists of an upper hinge plate 18 having an upper hinge pin 17 that protrudes downward, and a pin hole 19 formed in the upper right edge of the door 13 to receive the upper hinge pin 17. The pin hole 19 is recessed in a boss 20 that is embedded and fixed to the upper right edge surface of each door 13. The lower hinge mechanism 15 of the door hinge structure consists of a lower hinge plate 22 having a lower hinge pin (hinge pin) 21 that protrudes upward, a lower spacer 24 that is attached to the lower hinge plate 22 and has a first cam portion 23 that is inserted through the lower hinge pin 21 and fixed, and an upper spacer 26 that is fixed to the lower right edge of the door 13 and has a second cam portion 25 that engages with the first cam portion 23 when inserted through the lower hinge pin 21.

[0025] As shown in Figure 2, a first door support member 29A is fixed to the right edge of the upper wall 4A of the main body case 4, a second door support member 29B is fixed to the right edge of the intermediate frame 5, and a third door support member 29C is fixed to the right edge of the lower wall 4B of the main body case 4. Each of the first to third door support members 29A to 29C comprises a mounting plate 30 made of a vertical wall and a support plate 31 made of a horizontal wall formed in a bent shape extending forward from the upper end of the mounting plate 30. The support plate 31 is formed in the shape of a right-angled triangle that is long in the left-right direction, with the right-angle portion positioned to the right in a plan view and the right end protruding forward. Each door support member 29A to 29C is fixed to the main body case 4 by fastening the mounting plate 30 to the front of the main body case 4 with screws 32.

[0026] In this embodiment, the first door support member 29A constitutes the upper hinge plate 18 of the upper hinge mechanism 14 of the upper door 13, and the second door support member 29B constitutes the lower hinge plate 22 of the lower hinge mechanism 15 of the upper door 13. Furthermore, the second door support member 29B also serves as the upper hinge plate 18 of the upper hinge mechanism 14 of the lower door 13, and the third door support member 29C constitutes the lower hinge plate 22 of the lower hinge mechanism 15 of the lower door 13. As shown in Figure 3, the first door support member 29A has an upper hinge pin 17 protruding downward from the lower surface of the right front corner of the support plate 31. Similarly, the second door support member 29B has a lower hinge pin 21 protruding upward from the upper surface of the right front corner of the support plate 31, and an upper hinge pin 17 protruding downward from the lower surface. Similarly, the third door support member 29C has a lower hinge pin 21 protruding upward from the upper surface of the right front corner of the support plate 31. These first to third door support members 29A to 29C (upper and lower hinge plates 18 and 22) are formed from stainless steel by lost-wax casting.

[0027] As shown in Figure 4, on the upper surface of the support plate 31 that constitutes the lower hinge plate 22 (the second door support member 29B and the third door support member 29C), a recessed portion 33 having a receiving surface 33a is formed around the lower hinge pin 21. The recessed portion 33 is provided with a lock recess 34 that allows the insertion of the lock block 40 of the lower spacer 24 (described later), and a lock hole 35 into which the lock arm 39 of the lower spacer 24 engages. The lock recess 34 consists of a rectangular (polygonal) recess in plan view that is recessed in the recessed portion 33, and the lock hole 35 consists of a rectangular hole in plan view that is formed through the recessed portion 33. The lock recess 34 and the lock hole 35 are arranged side by side in a connected state, with the lock recess 34 located on the lower hinge pin 21 side.

[0028] The lower spacer 24 is molded from resin by a molding method and integrally comprises a cylindrical first cam portion 23, a rectangular flat plate-shaped spacer body 38 extending outward from the first cam portion 23, a pair of lock arms 39-39 extending downward from the tip of the spacer body 38 in the direction of extension for preventing detachment and rotation, and a lock block 40 for preventing rotation that protrudes downward from the lower surface of the spacer body 38. As shown in Figure 5, an insertion hole 41 through which the lower hinge pin 21 is inserted is opened in the center of the first cam portion 23. The first cam portion 23 is formed at equiangled positions from the center of rotation defined by the center of the lower hinge pin 21 and consists of three lower convex portions 42 having flat surfaces, lower inclined portions 43-43 having downward-sloping inclined surfaces on both sides of each lower convex portion 42, and a lower recess 44 having a flat surface formed between adjacent lower inclined portions 43-43.

[0029] The insertion hole 41 is surrounded by the lower convex portion 42, the lower inclined portion 43, and the lower recess 44. The flat surface of the lower convex portion 42, the inclined surface of the lower inclined portion 43, and the flat surface of the lower recess 44 form an annular cam surface 45 in plan view around the insertion hole 41. A vertical step is formed at the boundary between the lower inclined portion 43 and the lower recess 44 (see Figure 4). In Figure 5, when the diameter dimension of the design lower hinge pin 21, shown by the dashed line, is defined as D1 and the diameter dimension of the insertion hole 41 is defined as D2, the diameter dimension D2 is set to be larger than the diameter dimension D1, and the lower spacer 24 is mounted to the lower hinge plate 22 with a slight clearance between the lower hinge pin 21 and the insertion hole 41 (see Figures 1 and 7). The angle of rotation of the flat surface of the lower convex portion 42 and the angle of rotation of the inclined surfaces of the lower inclined portions 43, 43 are both set to 25°, while the angle of rotation of the lower concave portion 44 is set to 45°.

[0030] As shown in Figures 1 and 8, a pair of lock arms 39-39 are arranged side by side with a virtual axis L, defined by the extension direction of the spacer body 38 passing through the center of the lower hinge pin 21, in between them. As shown in Figures 6 and 9, each lock arm 39 includes an arm portion 46 formed in an inverted L-shape continuous with the tip of the spacer body 38, and a claw portion 47 protruding from the lower end of the arm portion 46 in opposite directions. Each arm portion 46 is formed to be elastically deformable in directions toward and toward each other. The claw portion 47 engages with the lower edge of the lock hole 35 when the lower spacer 24 is mounted on the lower hinge plate 22. As shown in Figure 8, the lock block 40 is formed in a hollow block shape that exhibits a trapezoidal shape in plan view, with the upper and lower bases of the trapezoid perpendicular to the aforementioned virtual axis L, and the upper base of the trapezoid positioned away from the insertion hole 41.

[0031] In the state shown in Figure 1, where the lower spacer 24 is attached to the lower hinge plate 22, the direction perpendicular to the virtual axis L in a plan view is defined as the width direction. At this time, as shown in Figure 8, the two sides of the lock recess 34 and lock hole 35 facing each other in the width direction are arranged parallel to the virtual axis L. When the vertical wall surface continuous with the two sides of the lock recess 34 is defined as the recess wall surface 34a, and the vertical wall surface continuous with the two sides of the lock hole 35 is defined as the hole wall surface 35a, the opening dimension W1 between the opposing recess wall surfaces 34a and 34a and the opening dimension W2 between the opposing hole wall surfaces 35a and 35a are set to be the same, and the recess wall surface 34a and the hole wall surface 35a are formed flush with each other.

[0032] The width dimension W3 of the upper base of the trapezoidal lock block 40 is set to be slightly smaller than the opening dimension W1, so that when the lock block 40 is inserted into the lock recess 34, either end of the upper base of the trapezoid is received by the recess wall surface 34a, thereby restricting the rotation of the lower spacer 24 around the lower hinge pin 21. In addition, the pair of lock arms 39-39 in the lower spacer 24, separated from the lower hinge plate 22 shown by the dashed line in Figure 9, have a width dimension W4 between the surfaces on which the claw portion 47 is formed that is set to be slightly larger than the opening dimension W2, so that the pair of lock arms 39-39 are elastically deformed in a direction toward each other and engage with the lock hole 35 in a state where they are in close contact with the hole wall surface 35a.

[0033] As shown in Figure 4, the upper spacer 26, which is fixed to the lower right edge of the door 13, is molded from resin using a molding method and integrally comprises a mounting base 51 formed in the shape of an elongated cylinder in plan view, a flange 52 formed to protrude from the lower end of the mounting base 51, and a cylindrical second cam portion 25 formed to bulge downward from the flange 52. An insertion hole 53 is opened in the center of the second cam portion 25, through which the lower hinge pin 21 is inserted, penetrating the mounting base 51 and the flange 52.

[0034] The second cam portion 25 is formed at equiangled positions from the center of rotation defined by the center of the lower hinge pin 21 and consists of three upper protrusions 54 having flat surfaces, upper inclined portions 55-55 having upward-sloping inclined surfaces on both sides of each upper protrusion 54, and an upper recess 56 having a flat surface formed between adjacent upper inclined portions 55-55. The insertion hole 53 is surrounded by the upper protrusions 54, upper inclined portions 55, and upper recess 56, and an annular cam surface 57 is formed around the insertion hole 53 in plan view by the flat surface of the upper protrusions 54, the inclined surface of the upper inclined portions 55, and the flat surface of the upper recess 56. A vertical step is formed at the boundary between the upper inclined portions 55 and the upper recess 56. The diameter of the insertion hole 53 is set to be slightly larger than the diameter of the lower hinge pin 21, and the upper spacer 26 is pivotally supported relative to the lower hinge plate 22 with a slight clearance between the lower hinge pin 21 and the insertion hole 53. The shape of the second cam portion 25 is the inverted shape of the first cam portion 23, and the angle width from the rotation center of the flat surface of the upper convex portion 54 and the angle width from the rotation center of the inclined surfaces of the upper inclined portions 55, 55 are both set to 25°, while the angle width from the rotation center of the upper concave portion 56 is set to 45°.

[0035] In the refrigerator 1 of this embodiment, which has the above configuration, the third door support member 29C is fixed to the front right edge of the lower wall 4B of the main body case 4 with screws 32, and the insertion hole 41 is aligned with the lower hinge pin 21 and the lower spacer 24 is dropped into the stepped portion 33 of the support plate 31. Subsequently, the pair of lock arms 39-39 are engaged with the lock hole 35 and the lock block 40 is inserted into the lock recess 34, thereby attaching the lower spacer 24 to the lower hinge plate 22. Next, the insertion hole 53 is aligned with the lower hinge pin 21 and the upper spacer 26 is dropped in together with the door 13 so that the first cam portion 23 and the second cam portion 25 interlock. This makes it possible to construct a lower hinge mechanism 15 that pivots and supports the door 13 of the lower storage compartment 3, as shown in Figures 3 and 6.

[0036] Next, the upper hinge pin 17 of the second door support member 29B is inserted into the pin hole 19, and the second door support member 29B is fixed to the front right edge of the intermediate frame 5 of the main case 4 with screws 32. This makes it possible to construct an upper hinge mechanism 14 that pivots and supports the door 13 of the lower storage compartment 3, as shown in Figure 3. The method for constructing the door 13 of the upper storage compartment 2 is simply that the third door support member 29C becomes the second door support member 29B, and the second door support member 29B becomes the first door support member 29A, so the explanation is omitted.

[0037] Next, the operation of the lower hinge mechanism 15 will be explained with reference to Figures 10(a) to (c). As shown in Figure 10(a), when the door 13 is in the fully closed position, the upper and lower ends of the upper inclined portion 55 of the second cam portion 25 coincide with the upper and lower ends of the lower inclined portion 43 of the first cam portion 23. When the door 13 is opened from this fully closed position, the cam surface 57 of the upper second cam portion 25 rotates counterclockwise in a plan view on the cam surface 45 of the lower first cam portion 23. That is, in Figure 10(a), the upper cam surface 57 moves to the right, the upper inclined portion 55 of the second cam portion 25 climbs up the lower inclined portion 43 of the first cam portion 23, and the upper convex portion 54 of the second cam portion 25 rides up on the lower convex portion 42 of the first cam portion 23 (Figure 10(b)). When the upper protrusion 54 rests on top of the lower protrusion 42 and the flat surfaces of both protrusions 42 and 54 are in contact, no assisting effect is exerted on the door 13, and the door 13 is held open in a neutral position.

[0038] From this state, when the door 13 is opened further, the upper projection 54 of the second cam portion 25 overcomes the lower projection 42 of the first cam portion 23, causing the upper inclined portion 55 of the second cam portion 25 to slide down the lower inclined portion 43 of the first cam portion 23, thereby assisting the automatic swinging operation of the door 13 to the fully open state. As shown in Figure 10(c), when the door 13 is fully open, a force is exerted that causes the upper inclined portion 55 of the second cam portion 25 to slide down along the lower inclined portion 43 of the first cam portion 23, i.e., the opening action after full opening. Conversely, when the door 13 is closed from the state shown in Figure 10(b), the upper projection 54 of the second cam portion 25 overcomes the lower projection 42 of the first cam portion 23, causing the upper inclined portion 55 of the second cam portion 25 to slide down the lower inclined portion 43 of the first cam portion 23, thereby assisting the automatic swinging operation of the door 13 to the fully closed state. As shown in Figure 10(a), when the door 13 is fully closed, a force is exerted that causes the upper inclined portion 55 of the second cam portion 25 to slide down along the lower inclined portion 43 of the first cam portion 23, that is, a closing action after full closure.

[0039] When the assisting force of the door 13 is exerted, that is, when the door 13 is operated to the closing or opening side from the state shown in Figure 10(b), and the upper inclined portion 55 of the second cam portion 25 slides down the lower inclined portion 43 of the first cam portion 23, the reaction force of the assisting force (rotational moment) around the lower hinge pin 21 that automatically swings the door 13 is transmitted to the first cam portion 23 via the second cam portion 25, and acts on the lower spacer 24 as a rotational moment in the opposite direction to the assisting force. Since the diameter dimension D1 of the lower hinge pin 21 is set to be slightly larger than the diameter dimension D2 of the insertion hole 41, the lower spacer 24 has room to be displaced by the amount of clearance relative to the lower hinge pin 21. When such a reaction force of the assisting force acts on the lower spacer 24, the lower spacer 24 moves and hits the lower hinge pin 21, producing a sound. Therefore, the door hinge mechanism of this embodiment is provided with a structure aimed at preventing such noise.

[0040] Specifically, as shown in Figures 1 and 5, slits 60 opening towards the insertion hole 41 are formed in each of the three lower recesses 44 of the lower spacer 24, and elastic arms 61 that can be elastically deformed in the radial direction of the hinge pin 21 are formed between the slits 60 and the insertion hole 41. The slit 60 is formed of a first slit 60A extending radially outward from the insertion hole 41 and a second slit 60B extending counterclockwise along the concentric circle of the insertion hole 41 in a plan view from the outer end of the first slit 60A. The slits 60 form the elastic arms 61 in a cantilever shape extending along the insertion hole 41, and the tips of the arms are configured to be able to be greatly elastically deformed in the radial direction. Each elastic arm 61 constitutes a part of the insertion hole 41, and a restricting body 62 that contacts the circumferential surface of the hinge pin 21 is provided projecting vertically from the surface of the elastic arm 61 facing the insertion hole 41 at its tip. The restrictor 62 is formed in a bulging shape from the elastic arm 61 toward the center of the insertion hole 41 and has a contact surface 63 consisting of an arcuate surface that contacts the circumferential surface of the hinge pin 21. The contact surface 63 consists of an arcuate surface with the same curvature as the diameter dimension D1 of the hinge pin 21. These three contact surfaces 63 are arranged at equiangled positions with respect to the center of the insertion hole 41.

[0041] In Figure 5, when the diameter of the circle inscribed in the restrictor 62, indicated by the dashed line, is defined as D3, when the lower spacer 24 is separated from the lower hinge plate 22, the diameter D3 is set to be smaller than the diameter D1 of the lower hinge pin 21. In other words, in the lower spacer 24 of this embodiment, the diameter D2 of the insertion hole 41 is set to be larger than the diameter D1 of the lower hinge pin 21, and the diameter D3 of the circle inscribed in the restrictor 62 is set to be smaller than the diameter D1 of the lower hinge pin 21. As a result, when the lower spacer 24 is attached to the lower hinge plate 22, a clearance is provided between the lower hinge pin 21 and the insertion hole 41, and the contact surface 63 of the restrictor 62 is in contact with the circumferential surface of the lower hinge pin 21. Furthermore, the regulating body 62 is pressed toward the lower hinge pin 21 by the elastic force of the elastic arm 61, so that the contact surface 63 is in close contact with the circumferential surface of the lower hinge pin 21.

[0042] With the lower spacer 24, which has restricting bodies 62 provided on an elastic arm 61 that forms part of the insertion hole 41, the contact surfaces 63 of the three restricting bodies 62 come into contact with the circumferential surface of the lower hinge pin 21, thereby positioning the lower spacer 24 so that the axis of the lower hinge pin 21 coincides with the center of the hole in the insertion hole 41. Even if a relatively large reaction force of the assisting force acts on the lower spacer 24 when the door 13 is assisting, the elastic arm 61 elastically deforms radially around the lower hinge pin 21, thereby cushioning the reaction force. Furthermore, the rotation of the lower spacer 24 around the lower hinge pin 21 is restricted by the engagement of a pair of lock arms 39-39 in the lock hole 35 and the insertion of a lock block 40 in the lock recess 34. As a result, the horizontal displacement of the lower spacer 24 relative to the lower hinge plate 22 is restricted, as is the rotation around the lower hinge pin 21.

[0043] As described above, in the door hinge structure of this embodiment, a slit 60 opening to the insertion hole 41 side is formed in each lower recess 44 constituting the first cam portion 23, and a cantilevered elastic arm 61 that can be elastically deformed in the radial direction of the lower hinge pin 21 is formed between the slit 60 and the insertion hole 41, and a restricting body 62 is provided projecting from each elastic arm 61 toward the center of the insertion hole 41, and the restricting body 62 comes into contact with the circumferential surface of the lower hinge pin 21. Therefore, even when a clearance is provided between the lower hinge pin 21 and the insertion hole 41, the lower spacer 24 can be positioned with respect to the lower hinge pin 21 by the restricting body 62, thereby restricting the displacement of the lower spacer 24. In this way, restricting the displacement of the lower spacer 24 with the restricting body 62 prevents the inner circumferential surface of the insertion hole 41 from impacting the lower hinge pin 21 due to the reaction force of the assisting force, thereby preventing noise from being generated by such impact. Furthermore, since a restrictor 62 is provided on the elastic arm 61 which is elastically deformable in the radial direction, even if the reaction force of the assisting force of the door 13 acts on the lower spacer 24, the elastic arm 61 elastically deforms radially around the lower hinge pin 21, cushioning the reaction force and preventing the restrictor 62 from being crushed and damaged. As described above, the door hinge structure of this embodiment prevents the displacement of the lower spacer 24 with the restrictor 62, and further prevents the restrictor 62 from being damaged with the elastic arm 61, thus preventing noise caused by the clearance between the lower hinge pin 21 and the insertion hole 41 of the lower spacer 24 over a long period of time.

[0044] Since the regulating body 62 is pressed toward the circumferential surface of the lower hinge pin 21 by the elastic restoring force of the elastic arm 61, even if the lower spacer 24 moves slightly due to the reaction force of the assisting force of the door 13, and one or two elastic arms 61 elastically deform radially outward of the lower hinge pin 21, the remaining elastic arm 61 elastically returns to its radially inward position, making it possible to constantly maintain contact between the lower hinge pin 21 and the regulating body 62, thereby more reliably preventing noise from occurring.

[0045] By setting the diameter D2 of the insertion hole 41 to be larger than the diameter D1 of the lower hinge pin 21, and setting the diameter D3 of the circle inscribed in the regulating body 62 to be smaller than the diameter D1 of the lower hinge pin 21, the door hinge structure can be easily constructed by simply inserting the lower hinge pin 21 through the insertion hole 41 and attaching the lower spacer 24 to the lower hinge plate 22, while providing clearance between the lower hinge pin 21 and the insertion hole 41, and pressing the regulating body 62 toward the circumferential surface of the lower hinge pin 21 with the elastic force of the elastic arm 61.

[0046] The tip of the arm is the part of the elastic arm 61 that has a relatively large amount of elastic deformation. With an elastic arm 61 that has a restricting body 62 provided on the tip of the arm on the side of the insertion hole 41, even if a large assisting reaction force acts on the elastic arm 61 via the restricting body 62, the reaction force can be reliably buffered.

[0047] Each elastic arm 61 is provided with one restrictor 62, and the contact surface 63 of each restrictor 62 is positioned at an equiangled position with respect to the center of the insertion hole 41. As a result, three contact surfaces 63 are evenly distributed on the circumferential surface of the lower hinge pin 21, allowing the lower spacer 24 to be reliably positioned with a small number of contact surfaces 63, regardless of the direction in which the lower spacer 24 attempts to move.

[0048] A pair of locking arms 39, 39 for preventing detachment and rotation are arranged side by side with a virtual axis L defined by the extension direction of the spacer body 38 passing through the center of the lower hinge pin 21 in between. Each locking arm 39 comprises an arm portion 46 formed to be elastically deformable in directions toward and toward each other, and a claw portion 47 projecting from the lower end of the arm portion 46 in opposite directions and engaging with the lower edge of the locking hole 35. Furthermore, since the pair of arm portions 46, 46 are engaged with the locking hole 35 in a state where they are elastically deformed toward each other, the elastic restoring force of the arm portion 46 can press each locking arm 39 against the inner surface of the locking hole 35. As a result, no clearance is formed between each locking arm 39 and the locking hole 35, preventing the lower spacer 24 from rattling around the hinge pin 21.

[0049] The lock block 40 is received by the vertical recess walls 34a, 34a of the lock recess 34, which are continuous on two sides parallel to the virtual axis L in a plan view. This restricts the rotation of the lower spacer 24 around the lower hinge pin 21. Therefore, even if one of the lock arms 39 breaks, the lock block 40 can prevent the lower spacer 24 from rotating around the lower hinge pin 21, maintaining the engaged state of the remaining lock arm 39. In addition, since the lock block 40 is formed in a trapezoidal block shape with its upper and lower bases arranged perpendicular to the virtual axis L in a plan view, the end of the upper base portion of the trapezoidal block can be brought into contact with the lock recess 34, reducing the contact area between the lock block 40 and the lock recess 34. This reduces the noise caused by the lock block 40 impacting the lock recess 34.

[0050] In addition to the above, the shape of the slit 60 is not limited to that of the above embodiment. The restrictor 62 can also be provided on the surface of the elastic arm 61 on the insertion hole 41 side, either at the base end or in the center; in short, it just needs to be provided on a part of the hinge pin 21 that is elastically deformable in the radial direction. Furthermore, the restrictor 62 may be provided on a part of the elastic arm 61 in the vertical direction, and multiple restrictors can be provided at a distance from each other vertically. An elastic arm having a restrictor similar to that of the lower spacer 24 can also be provided in the upper recess 56 of the upper spacer 26. The door hinge structure according to the present invention can be applied not only to the hinge structure of a refrigerator's swing door, but also to the hinge structure of a freezer, cooler, warmer, and other storage cabinets. [Explanation of Symbols]

[0051] 1. Storage room (refrigerator) 12. Openings (entrances / exits) 13 Doors 21. Hinge pin (lower hinge pin) 22. Hinge plate (lower hinge plate) 23 First cam section 24 Lower spacer 25 Second cam section 26 Upper spacer 31 Support plate 34 Lock recess 34a Recessed wall surface 35 lock holes 38 Spacer body 39 Lock Arm 40 Rock Blocks 41 Through hole 42 Lower protrusion 43 Lower slope 44 Lower recess 46 Arm section 47. Nail area 60 slits 61 Elastic Arm 62 Regulatory bodies D1 Hinge pin (lower hinge pin) diameter dimension D2 Diameter of the insertion hole D3 Diameter dimension of a circle inscribed in a regulating body L virtual axis

Claims

1. A hinge plate (22) having a hinge pin (21) that protrudes upward and attached to the lower end of the side edge of the opening (12) of the storage compartment (1), A lower spacer (24) having a first cam portion (23) that is attached to the hinge plate (22) and fixed in a state where it is inserted through the hinge pin (21), An upper spacer (26) is fixed to the lower end of the side edge of the door (13) that opens and closes the opening (12) of the storage room (1), and has a second cam portion (25) that engages with the first cam portion (23) when inserted through the hinge pin (21), A door hinge structure comprising: The first cam portion (23) is formed at equiangled positions from the center of rotation and consists of three lower protrusions (42) having flat surfaces, lower inclined portions (43) having downward-sloping surfaces on both sides of each lower protrusion (42), and a lower recess (44) having a flat surface formed between adjacent lower inclined portions (43). An insertion hole (41) through which a hinge pin (21) is inserted with clearance is provided, surrounded by these lower protrusions (42), lower inclined portions (43), and lower recess (44). A slit (60) opening to the insertion hole (41) is formed in each lower recess (44), and a cantilevered elastic arm (61) that is elastically deformable in the radial direction of the hinge pin (21) is formed between the slit (60) and the insertion hole (41). A door hinge structure characterized in that each elastic arm (61) has a regulating body (62) protruding toward the center of the insertion hole (41), and the regulating body (62) is in contact with the circumferential surface of the hinge pin (21).

2. The door hinge structure according to claim 1, wherein the regulating body (62) is pressed toward the circumferential surface of the hinge pin (21) by the elastic restoring force of the elastic arm (61).

3. When the diameter of the hinge pin (21) is defined as (D1), the diameter of the insertion hole (41) as (D2), and the diameter of the circle inscribed in the restricting body (62) when the lower spacer (24) is separated from the hinge plate (22) is defined as (D3), The door hinge structure according to claim 2, wherein the diameter dimension (D2) is set to be larger than the diameter dimension (D1), and the diameter dimension (D3) is set to be smaller than the diameter dimension (D1).

4. The door hinge structure according to claim 1, wherein the restricting body (62) is provided on the tip of the elastic arm (61) on the side of the insertion hole (41).

5. The lower spacer (24) comprises a spacer body (38) formed in the shape of a flat plate extending outward from the first cam portion (23), and a pair of locking arms (39, 39) extending downward from the tip of the spacer body (38) in the direction of extension, for preventing detachment and rotation. The hinge plate (22) includes a support plate (31) that is attached to the lower end of the side edge of the opening (12) of the storage compartment (1), and the support plate (31) has a locking hole (35) that penetrates vertically through the support plate (31) into which the locking arm (39) engages. The pair of locking arms (39, 39) are arranged side by side with a virtual axis (L) defined by the extension direction of the spacer body (38) passing through the center of the hinge pin (21) in between. Each lock arm (39) comprises an arm portion (46) formed to be elastically deformable in directions toward and toward each other, and a claw portion (47) that protrudes from the lower end of the arm portion (46) in opposite directions and engages with the lower edge of the lock hole (35). A door hinge device according to any one of claims 1 to 4, wherein a pair of arm portions (46, 46) are engaged with a lock hole (35) in a state in which they are elastically deformed in a direction toward each other.

6. The lower spacer (24) is equipped with a positioning lock block (40) that protrudes downward from the lower surface of the spacer body (38). The support plate (31) has a recessed lock recess (34) which is a polygonal recess having two sides parallel to the virtual axis (L) in a plan view, allowing the insertion of the lock block (40). The lock block (40) is received by the vertical recess walls (34a, 34a) continuous with the two parallel sides, thereby restricting the rotation of the lower spacer (24) around the hinge pin (21). The door hinge structure according to claim 5, wherein the lock block (40) is formed in the shape of a trapezoidal block, with its upper and lower bases arranged in a direction perpendicular to the virtual axis (L) in a plan view.

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