JP2978129B2 - 2-axis back hinge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hinge for supporting a door, which is flush with a fixed frame such as a cabinet body or a switchboard storage box body, so that it can be opened up to 180.degree. In particular, an intermediate connection plate having a substantially U-shaped cross section is interposed between two fixed pivots serving as rotation centers between a fixed-side blade attached to the fixed frame and a rotating-side blade attached to the door. It relates to a two-axis back hinge.

[0002]

2. Description of the Related Art A hinge for supporting a door, which is flush with a fixed frame such as a cabinet body or a switchboard storage box body, so that the door can be opened up to 180.degree. Between the fixed-side blade attached to the door and the rotating-side blade attached to the door.
2. Description of the Related Art There is known a two-axis back hinge in which an intermediate connecting plate having a substantially U-shaped cross section is interposed via two parallel pivots. The two-axis rear hinge is configured such that the intermediate connecting plate rotates 90 ° with respect to the fixed-side wing plate, and the turning-side wing plate rotates 90 ° with respect to the intermediate connecting plate, so that the door moves 180 ° relative to the fixed frame. ° open.

[0003] Due to having two pivots, the edge of the door may collide with the edge of the fixed frame if, for example, the turning blade starts to rotate before the intermediate connecting plate. This phenomenon is remarkable in a configuration in which the edge of the door and the edge of the fixed frame body partially overlap each other at the closed position and have high hermeticity. This collision must be surely prevented because it causes distortion of the door and the fixed frame, and peeling and damage of the coating and the protective coating. However, in the conventional two-axis rear hinge, there is no structure that reliably regulates the rotation order of the intermediate connecting plate and the rotation-side blade.

Japanese Unexamined Patent Publication No. 7-293096 discloses a biaxial type in which rotation of an intermediate connecting plate with respect to a fixed-side blade and rotation of a rotating-side blade with respect to an intermediate connecting plate are performed in a predetermined order through the intermediation of a lock lever. Hinge is described. However, this is a hinge mounted on the upper and lower end surfaces of the door, and cannot be applied to a back hinge mounted on the inside of the door.

[0005]

Therefore, according to the present invention, when the opening operation is performed, the intermediate connecting plate is first moved to the fixed-side vane plate by 9 degrees.
After the rotation by 0 °, the rotation side vane plate is rotated by 90 ° with respect to the intermediate connecting plate, so that the door is moved by 1 degree with respect to the fixed frame.
It is opened up to 80 °, and during the closing operation, after the rotating blade is rotated 90 ° with respect to the intermediate connecting plate, the intermediate connecting plate is rotated 90 ° with respect to the fixed blade so that the door reaches the closed position. Another object of the present invention is to provide a biaxial back hinge capable of reliably restricting the rotation order of the intermediate connecting plate and the rotating blade.

[0006]

A two-axis back hinge 1 includes a fixed blade 2, a rotating blade 3, and both blades 2, 3 pivotally supported by a fixed pivot 4 and a rotating pivot 5. An intermediate connecting plate 6,
A lock lever 8 pivotally supported by a pivot 7 on the intermediate connecting plate 6
And a spring 9 interposed between the intermediate connecting plate 6 and the lock lever 8. The hinge 1 supports the door D with respect to the fixed frame F inside. The door D is disposed substantially flush with the fixed frame F in the closed position, passes through a half-open position of approximately 90 ° with respect to the fixed frame F, and then reaches a fully open position parallel to the fixed frame F. 180 degrees can be opened.

The fixed-side blade 2 has a mounting plate 10 and a bearing plate 11, and the mounting plate 10 is fixed to a mounting surface inside the fixed frame F. The bearing plate portion 11 is formed such that the upper and lower edges of the mounting plate portion 10 are substantially perpendicular to the mounting plate portion 10.
It extends horizontally to the side and supports a fixed side pivot 4 in the middle.
At the edge of the bearing plate portion 11, a contact surface 12 at the time of closing, a sliding arc surface 13, a step portion 14, and a contact surface 15 at the time of opening are successively continuously provided from one end to the other end. Is formed. The closing abutment surface 12 is located parallel to the mounting plate portion 10 and outside the fixed-side pivot 4. The sliding arc surface 13 is
From the end of the closing contact surface 12 in an angle range slightly smaller than 90 °. Step 14 is
It falls from the end of the sliding arc surface 13. The open contact surface 15 is continuous with the step portion 14 and extends at a predetermined inclination angle with respect to the mounting plate portion 10.

[0008] The rotating blade 3 has a mounting plate 16 and a bearing plate 17 and is fixed to the mounting surface inside the door D by the mounting plate 16. The bearing plate portion 17 extends horizontally from the upper and lower edges of the mounting plate portion 16 to the intermediate connecting plate 6 substantially at right angles to the mounting plate portion 16 and supports the pivot shaft 5 at the middle. A regulating arc surface 18 and an engaging step 19
And the closing pressing surface 20 are continuously formed from one end to the other end. The regulating arc surface 18 rises in an arc shape concentric with the rotation-side pivot 5 in an angle range of approximately 90 ° from one end. The engagement step 19 falls from the end of the regulating arc surface 18 and continues to the closing pressing surface 20. The closing pressing surface 20 extends to the other end side in parallel with the mounting plate portion 16.

The intermediate connecting plate 6 is bent in a substantially U-shape in plan view, and includes an intermediate plate portion 21, first and second connecting plate portions 22 and 23 on both sides thereof, and a stopper piece 24. I do.
The intermediate plate portion 21 supports the pivot 7 of the lock lever 8.
The first connection plate portion 22 is bent substantially at right angles to the intermediate plate portion 21 from one end edge of the intermediate plate portion 21 and extends vertically, and is pivotally attached to the fixed-side wing plate 2 by the fixed-side pivot 4 at the end edge. ing. The second connecting plate portion 23 is bent substantially perpendicularly to the intermediate plate portion 21 from the other end edge of the intermediate plate portion 21 and extends vertically,
At the end edge, it is pivotally connected to the rotation-side vane plate 3 by the rotation-side pivot 5. The stopper piece 24 extends outward from the edge of the second connecting plate portion 23 at a substantially right angle thereto.

A pair of lock levers 8 are horizontally provided along the upper and lower edges of the intermediate connecting plate 6 so as to face each other vertically and are connected to each other by a connecting portion 25. Lock lever 8
Is bent substantially in a U-shape in plan view substantially along the outside of the intermediate connecting plate 6, and the intermediate portion is pivotally supported by the intermediate connecting plate 6 by a vertical pivot 7. The lock lever 8 extends toward the fixed-side blade 2 and engages with the first engaging portion 29.
At one end, a second engaging portion 30 extending toward and engaging with the rotary blade 3 at the other end, and the first engaging portion 29 is always fixed by the spring 9. It is urged to rotate so as to contact the side blades 2.

The first engaging portion 29 has a contact end surface 31 and a contact side surface 32 orthogonal to the contact end surface 31. Contact end face 31
Abuts on the closed contact surface 12 of the fixed-side vane plate 2 in the closed position of the door D. The contact side surface 32 continuously extends at a right angle to the inner end of the contact end surface 31. The contact side 31 is
From the closed position of the door D to the substantially half-open position, the sliding member slides on the sliding arc surface 13 of the fixed-side blade 2, and the intermediate connecting plate 6 and the lock lever 8 rotate integrally with the fixed-side blade 2. So that the operation is regulated. When the intermediate connecting plate 6 and the lock lever 8 rotate relative to each other by the force of the spring 9 at the end of the sliding arc surface 13 and fall down to the stepped portion 14, the opening contact surface 15
, And the contact end face 31 is engaged with the step portion 14.

The second engaging portion 30 has a latch portion 33 and a tip surface 34. The latch portion 33 is provided so as to be able to be disengaged from the engaging step portion 19 of the rotating blade 3, and is provided with a door D.
From the closed position to the substantially half-open position, that is, until the contact side surface 32 is disengaged from the sliding arc surface 13, the lock lever 8 and the intermediate connecting plate 6 are integrated with the engaging step 19 of the rotating blade 3. Is rotated around the fixed side pivot 4. When the lock lever 8 is relatively rotated with respect to the intermediate connecting plate 6 by a spring force at a position where the contact side surface 32 is displaced from the sliding arc surface 13, the latch portion 33
Is disengaged from the engagement step portion 19, and thereafter, the turning-side vane plate 3 is allowed to independently turn around the turning-side pivot shaft 5 with respect to the intermediate connecting plate 6 until the door D is fully opened. The front end surface is in sliding contact with the regulating arc surface 18 while the turning side vane plate 3 turns from the fully open position of the door D to almost the half open position, and does not rotate the lock lever 8 relative to the intermediate connecting plate 6. When the distal end surface 34 deviates from the regulating arc surface 18 in the substantially half-open position, the lock lever 8
Is allowed to rotate relative to the intermediate connecting plate 6, the engagement between the contact end surface 31 and the step portion 14 is released, and the lock lever is pushed by the closing pressing surface 20 of the rotating blade 3 to the closed position. 8 and the intermediate connecting plate 6 are integrally rotated about the fixed side pivot 4.

When the door D is opened, the door D is half-opened about the fixed side pivot 4, then the door D is fully opened about the pivot side pivot 5, and when the door D is closed, the reverse is performed. The door D is opened halfway around the pivot shaft 5 at the center, and the turn sequence is controlled so that the door D is closed around the pivot shaft 4 at the center.
The shaft type back hinge 1 was configured.

[0014]

Embodiments of the present invention will be described with reference to the drawings. 1 to 6 are cross-sectional plan views sequentially showing the operation of the biaxial back hinge, FIG. 7 is a rear view of the biaxial back hinge, FIG. 8 is a perspective view of the fixed-side blade, and FIG. FIG. 9 is a perspective view of the intermediate connecting plate, and FIG. 10 is a perspective view of the lock lever.

The biaxial back hinge 1 includes a fixed-side blade 2, a rotating-side blade 3, an intermediate connecting plate 6 for connecting the two blades 2, 3 via pivots 4 and 5, and an intermediate connecting plate. 6 includes a lock lever 8 pivotally supported by a pivot 7, and a spring 9 interposed between the intermediate connecting plate 6 and the lock lever 8. Hinge 1
Supports the door D on the inside with respect to a fixed frame F such as a cabinet body or a switchboard storage box body. As shown in FIG. 1, the door D is disposed substantially flush with the fixed frame 1 in the closed position, passes through a half-open position (FIG. 3) of approximately 90 ° with respect to the fixed frame F, and It can be opened almost 180 ° to a fully open position (FIG. 4) parallel to the body F.

The fixed-side blade 2 has a mounting plate 10 and a bearing plate 11, and the mounting plate 10 is generally vertically fixed to a mounting surface inside the fixed frame F. The bearing plate 11 extends horizontally from the upper and lower edges of the rectangular mounting plate 10 to the intermediate connecting plate 6 side, and supports the fixed-side pivot 4 in the middle. Bearing plate 11
Has a cam edge surface 35 facing the intermediate connecting plate 6 side. The cam edge surface 35 has a closed contact surface 12 and a sliding circular surface 13.
, A step portion 14 and an abutment surface 15 at the time of opening, and are formed continuously from one end to the other end. The closing contact surface 12 is located parallel to the mounting plate portion 10 and outside the fixed-side pivot 4 (left side in FIG. 1). Sliding arc surface 1
Numeral 3 stands up from the end of the closing contact surface 12 in an angle range slightly smaller than 90 ° from the end of the closing contact surface 12 in a circular arc concentric with the fixed-side pivot 4. The step portion 14 falls from the end of the sliding arc surface 13. The open contact surface 15 is continuous with the step portion 14 and extends at a predetermined inclination angle with respect to the mounting plate portion 10.

The turning blade 3 includes a mounting plate 16 and a bearing plate 17, and is generally vertically fixed to the mounting surface inside the door D by the mounting plate 16. The bearing plate 17 extends horizontally from the upper and lower edges of the rectangular mounting plate 16 toward the intermediate connecting plate 6, and supports the pivot shaft 5 at the middle. The bearing plate portion 17 has a cam edge surface 36 facing the intermediate connecting plate 6 side. The cam edge surface 36 includes the regulating arc surface 18, the engaging step 19, and the closing pressing surface 20, and is formed continuously from one end (the left side in FIG. 1) to the other end. The regulating arc surface 18
It rises in a circular arc shape concentric with the pivot shaft 5 in an angle range of about 90 ° from one end side. The engagement step 19 falls from the end of the regulating arc surface 18 and continues to the closing pressing surface 20. The closing pressing surface 20 extends to the other end side in parallel with the mounting plate portion 16.

The intermediate connecting plates 6 are bent in a substantially U-shape in plan view, and each has a rectangular intermediate plate portion 21 and first intermediate portions 21 on both sides thereof.
And the second connecting plate portions 22 and 23 and the stopper piece 24. The intermediate plate portion 21 supports the pivot 7 of the lock lever 8 with a bearing projection 37 extending vertically and projecting horizontally from the upper and lower edges to the back. The first connecting plate portion 22 includes an intermediate plate portion 21.
Is bent substantially at a right angle from one end edge and extends vertically, and is pivotally attached to the fixed-side vane plate 2 at a fixed-side pivot 4 at the end edge. The second connecting plate portion 23 is bent substantially at a right angle from the other end edge of the intermediate plate portion 21 and extends vertically, and is pivotally attached to the turning-side wing plate 3 by the turning-side pivot 5 at the end edge. The stopper piece 24 extends outward at a substantially right angle from the edge of the second connecting plate 23.

A pair of lock levers 8 are provided horizontally and vertically opposite each other along the upper and lower edges of the intermediate connecting plate 6 and are connected to each other by a connecting portion 25 which is perpendicular to each other. The lock lever 8 is bent in a substantially U-shape in plan view so as to extend substantially along the outside of the intermediate connecting plate 6, and has an intermediate body 26 and legs 27 and 28 at both ends thereof. The body portion 26 is arranged so as to extend along the back surface of the intermediate plate portion 21 of the intermediate connection plate 6, and the intermediate portion is pivotally supported by the intermediate connection plate 6 by the pivot 7. One leg 27 extends at a right angle to the trunk 26, is disposed along the outer surface of the connecting plate 22, and has a first engaging portion 29 provided on the distal end side. The other leg 28
Extends slightly from the end of the body portion 26 in the same direction as the leg portion 27, is disposed substantially along the connecting plate portion 23, and is provided with a second engaging portion 30 on the distal end side. The lock lever 8 is rotationally urged by the spring 9 so that the first engagement portion 29 is always in contact with the fixed-side blade 2.

The first engaging portion 29 has a contact end surface 31 and a contact side surface 32 orthogonal to the contact end surface 31. Contact end face 31
Abuts against the closed contact surface 12 of the fixed-side blade 2 at the closed position of the door D (FIG. 1). The contact side surface 32 continuously extends at a right angle to the inner end of the contact end surface 31. The contact side surface 32 slides on the sliding arc surface 13 of the fixed-side blade 2 from the closed position of the door D (FIG. 1) to a substantially half-open position (FIG. 3) (FIG. 2). During the sliding, the intermediate connecting plate 6 and the lock lever 8 rotate integrally with the fixed-side blade 2. When the support falls off the step 14 at the end of the sliding arc surface 13, the lock lever 8 is moved against the intermediate connecting plate 6 by the force of the spring 9.
Is relatively rotated counterclockwise about the pivot 7, and the contact side surface 3 is rotated.
2 comes into contact with the contact surface 15 when opened, and the contact end surface 31
4 is engaged.

The second engaging portion 30 has a latch portion 33 and a tip surface 34. The latch portion 33 is provided so as to be able to engage and disengage with the engaging step portion 19 of the rotating blade plate 3. The latch portion 33 is provided between the closed position (FIG. 1) of the door D and a substantially half-open position (FIG. 3), that is, until the contact side surface 32 is disengaged from the sliding arc surface 13. And the lock lever 8 and the intermediate connecting plate 6 are integrally rotated clockwise about the fixed pivot 4. Contact side 32
When the lock lever 8 is relatively rotated with respect to the intermediate connecting plate 6 by the force of the spring 9 at a position (FIG. 3) outside the sliding arc surface 13, the latch portion 33 is disengaged from the engaging step portion 19, and thereafter. Until the door D is fully opened (FIG. 4), the turning-side wing plate 3 is turned.
About the intermediate connecting plate 6 independently. The tip end surface 34 is provided with the regulating arc surface 1 during the rotation of the turning-side vane plate 3 from the fully open position (FIG. 4) of the door D to the almost half-open position (FIG. 3).
8 (FIG. 5), and the lock lever 8 is not rotated relative to the intermediate connecting plate 6. When the distal end surface 34 deviates from the regulating arc surface 18 at the substantially half-open position (FIG. 3),
Is lost, the relative rotation with respect to the intermediate connecting plate 6 is performed in the clockwise direction, and the engagement between the contact end surface 31 and the step portion 14 is released. Then, the distal end surface 34 is pressed by the closing pressing surface 20, and the lock lever 8 and the intermediate connecting plate 6 integrally rotate counterclockwise around the fixed side pivot 4 to the closed position (FIG. 1).

In the state shown in FIG. 1 in which the door D is in the closed position, the fixed blade 2 and the rotating blade 3 are arranged flush with each other, and the contact end surface 31 of the lock lever 8 is fixed to the fixed blade 2.
, The abutment side surface 32 abuts on the sliding arc surface 13, and the latch portion 33 engages with the engagement step 19 of the rotating blade 3. In this state, as shown in FIG. 2, when the door D is turned clockwise and opened, the intermediate connecting plate 6 is pulled by the rotating blade 3 and rotates clockwise about the pivot 4 at the same time as the engagement. The latch portion 33 is pulled by the step portion 19, and the lock lever 8 also rotates clockwise. The lock lever 8 rotates around the axis of the pivot 4 with the same radius by sliding the contact side surface 32 against the sliding arc surface 13, and thus rotates integrally with the intermediate connecting plate 6 without changing the relative position.

Immediately before the door D reaches the half-open position shown in FIG. 3 where the door D is arranged at 90 ° with respect to the fixed frame F, the contact side surface 32 of the lock lever 8 is disengaged from the sliding arc surface 13. With this force, a relative rotation occurs around the pivot 7 between the lock lever 8 and the intermediate connecting plate 6, the latch portion 33 is disengaged from the engaging step portion 19, and the rotating blade 3 becomes free. And
The first connecting plate portion 22 of the intermediate connecting plate 6 comes into contact with the mounting plate portion 10 of the fixed-side vane plate 2 to stop, and the lock lever 8 is stopped.
Abuts against the contact surface 15 when the fixed-side blade 2 is opened.

When the door D is further opened, the rotating blade 3 rotates about the pivot 5 and the mounting plate 16 comes into contact with the second connecting plate 23 of the intermediate connecting plate 6 in the fully opened state in FIG. Stop. In this state, the door D is disposed in parallel with the fixed frame F.

Next, when the door D is closed from the fully opened state, the rotating blade 3 first rotates approximately 90 ° counterclockwise about the pivot 5, and the mounting plate 16 is moved to the stopper piece 24 of the intermediate connecting plate 6. (FIG. 6). During this time, as shown in FIG. 5, the distal end surface 34 of the lock lever 8 slides on the regulating arc surface 18, and the lock lever 8 does not change its relative position with the intermediate connecting plate 6. When the distal end surface 34 is disengaged from the regulating arc surface 18 immediately before the mounting plate portion 16 comes into contact with the stopper piece 24, as shown in FIG. 8 and the intermediate connecting plate 6 rotate relative to each other about the pivot 7, and the contact end surface 31 of the lock lever 8 is disengaged from the step portion 14 of the fixed-side blade 2. Thereafter, the intermediate connecting plate 6 rotates counterclockwise about the pivot 4 to reach the closed position shown in FIG.

[0026]

As described above, according to the present invention, during the opening operation, the intermediate connecting plate 6 is first rotated by 90 ° with respect to the fixed-side blade 2 and then turned with respect to the intermediate connecting plate 6. By rotating the plate 3 by 90 °, the door D is fixed to the fixed frame F.
To the intermediate connecting plate 6 during the closing operation, the rotating side vane plate 3 is rotated 90 °,
The rotation order of the intermediate connecting plate 6 and the rotating blade 3 is reliably regulated by the intermediation of the lock lever 8 so that the intermediate connecting plate 6 rotates 90 ° with respect to the fixed-side blade 2 and the door D reaches the closed position. As a result, the collision between the edge of the door D and the edge of the fixed frame F can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view of a biaxial back hinge in a closed state of a door.

FIG. 2 is a cross-sectional plan view of a biaxial back hinge when the door is being opened.

FIG. 3 is a cross-sectional plan view of a biaxial back hinge in a half-open state of a door.

FIG. 4 is a cross-sectional plan view of a biaxial back hinge in a fully opened state of a door.

FIG. 5 is a cross-sectional plan view of the biaxial back hinge when the door is being closed.

FIG. 6 is a cross-sectional plan view of the biaxial back hinge when the door is being closed.

FIG. 7 is a rear view of the biaxial back hinge.

FIG. 8 is an exploded perspective view of a biaxial back hinge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 2-axis back hinge 2 Fixed-side blade 3 Rotation-side blade 4 Fixed-side pivot 5 Rotation-side pivot 6 Intermediate connecting plate 7 Pivot 8 Lock lever 9 Spring 10 Mounting plate 11 Bearing plate 12 Closed contact surface 13 Sliding arc surface 14 Step portion 15 Opening contact surface 16 Mounting plate portion 17 Bearing plate portion 18 Restricted arc surface 19 Engagement step portion 20 Closed pressing surface 21 Intermediate plate portion 22 First connection plate portion 23 Second Connecting plate portion 24 Stopper piece 25 Connecting portion 29 First engaging portion 30 Second engaging portion 31 Contact end surface 32 Contact side surface 33 Latch portion 34 Tip surface D Door F Fixed frame

Claims (1)

(57) [Claims] 1. A fixed frame, substantially flush with the fixed frame in a closed position, and substantially 90 degrees from the fixed frame.
A half-open position, and a biaxial back hinge that connects a door that can be opened by approximately 180 ° to a fully open position parallel to the fixed frame body at the inside thereof, wherein a mounting plate portion is provided inside the fixed frame body. A fixed-side wing plate to be fixed, a turning-side wing plate having a mounting plate portion fixed to the inside of the door, and the mounting plate portion being disposed substantially flush with the mounting plate portion of the fixed-side wing plate in a closed position of the door; Bending in a substantially U-shape in plan view, one end of the side is pivotally attached to the fixed-side vane by a vertical fixed-side pivot, and the other end is pivotally attached to the pivot-side vane by a vertical pivot-side pivot. The intermediate connecting plate is bent substantially in a U-shape in plan view substantially along the outside of the intermediate connecting plate, and the intermediate portion is horizontally pivotally supported along the upper and lower edges of the intermediate connecting plate by a vertical pivot. A first engaging portion that extends toward and engages with the fixed-side blade at one end side; And a pair of upper and lower opposing lock levers extending toward the rotation-side vane plate and engaging therewith, and mutually coupled by a linking portion. A spring for constantly bringing the first engagement portion into contact with the fixed-side blade, wherein the fixed-side blade is fixed vertically to a mounting surface of the fixed frame; A pair of bearing plate portions extending horizontally at the upper and lower edge portions of the plate portion to the intermediate connection plate side and supporting the fixed side pivot in the middle, wherein the turning side blade is perpendicular to the mounting surface of the door. A fixing plate portion to be fixed, and a pair of opposed bearing plate portions extending horizontally at the upper and lower edges of the mounting plate portion to the intermediate connecting plate side and supporting the pivot shaft in the middle, On the edge of the bearing plate portion, a closing contact surface parallel to the mounting plate portion is provided. Continuously attached to the sliding arc surface via a sliding arc surface rising from the end of the contact surface in an angle range slightly smaller than 90 ° concentrically with the fixed side pivot and a step falling from the end of the sliding arc surface An opening contact surface extending at a predetermined inclination angle with respect to the plate portion is sequentially formed from one end side to the other end side; and at the edge of the bearing plate portion of the turning side blade, the turning side pivot is provided. Approximately 90 ° concentrically with the pivot shaft from the inner position
The regulating arc surface rising in the angle range of the above, and the closing pressing surface that extends from the end of the regulating arc surface to the regulating arc surface and extends in parallel with the mounting plate portion through the engaging step portion extending from the end of the regulating arc surface, from one end side. The intermediate connecting plate is formed continuously to the other end side, and the intermediate connecting plate is disposed parallel to the mounting plate portion of the fixed-side blade and the rotating-side blade at the closed position of the door, and supports a pivot of the lock lever. A vertical intermediate plate portion to be bent substantially perpendicularly to the intermediate plate portion from one edge of the intermediate plate portion to extend vertically, and at a right angle to the mounting plate portion of the fixed-side wing plate at the closed position of the door. A first connecting plate portion pivotally attached to the fixed-side wing plate at an edge so as to be arranged at the edge, and extending substantially perpendicularly to the intermediate plate portion from the other end edge of the intermediate plate portion so as to extend vertically; In the closed position of the door, it is arranged at right angles to the mounting plate A second connecting plate portion pivotally attached to the rotation-side vane plate at an edge so as to be disposed, and extending outward from the edge of the second connecting plate portion at a substantially right angle to the connecting plate portion; A stopper piece that abuts on the mounting plate portion of the turning-side wing plate from a closed position of the door to a half-open position, wherein the first engagement portion of the lock lever is fixed at the closed position of the door. When the side vane plate is closed, the contact end surface that comes into contact with the contact surface and a right angle continuous with the inner end of the contact end surface, and the lock lever is integral with the intermediate connecting plate from the closed position to the almost half open position with respect to the fixed side vane plate. While rotating, it slides on the sliding arc surface, falls to the step at the end of the sliding arc surface, contacts the contact surface when open, and is arranged to engage the contact end surface with the step. And a second engaging portion of the lock lever is substantially half-opened from a closed position of the door. That is, the lock lever and the intermediate connecting plate are integrally rotated with respect to the fixed-side vane plate by engaging with the engaging step portion of the pivot-side vane plate until the contact side surface is disengaged from the sliding arc surface. When the lock lever is rotated relative to the intermediate connecting plate by a spring force at a position where the contact side surface is out of the sliding arc surface, the lock lever is disengaged from the engaging step portion, and the turning side wing plate is moved to the fully opened position of the door. And a latch portion allowing independent rotation with respect to the door, and an intermediate connection plate of the lock lever which is in sliding contact with the regulating arc surface while the rotation-side blade rotates from a fully open position to a substantially half-open position of the door. Relative to the intermediate connecting plate of the lock lever and disengagement of the lock lever from the fixed-side wing plate by allowing the lock lever to rotate relative to the intermediate connecting plate to the closed position after substantially engaging the engagement step at the half-open position. And a front end surface that allows relative rotation between the intermediate connecting plate and the fixed-side wing plate. During the opening operation of the door, the door is half-opened about the fixed-side pivot, and then the door is fully opened about the pivot-side pivot. A two-axis back hinge, wherein the hinge is half-opened and then the rotation order is regulated so as to close the door about the fixed-side pivot.