Spring-locked hinge mechanism

Abstract

To provide a hinge mechanism that allows a difference in torque depending on the rotation direction and allows an operator to arbitrarily switch the torque during rotation. [Solution] The hinge mechanism comprises an axis member 10, multiple lock springs 20, a fixed member 30, a rotating member 40, and a retaining member 50, and is structured so that when torque in the tightening direction is applied to the rotating member, the rotating member does not rotate in the tightening direction if the torque is below a specified value, and rotates in the tightening direction if the torque exceeds the specified value, while when torque in the loosening direction is applied to the rotating member, the rotating member rotates in the loosening direction.Free end locking portions 52 that can lock the free ends 22 of each lock spring on the loosening side are provided on the retaining member, and the torque when rotating the rotating member can be adjusted by switching between a locked state in which the free ends 22 are not locked by the free end locking portions 52, and an unlocked state in which the free ends 22 are locked by the free end locking portions.

Description

Technical Field

[0001] The present invention relates to a spring lock type hinge mechanism capable of adjusting torque by using a spring lock mechanism.

Background Art

[0002] As a mechanism for connecting two members in a relatively rotatable state, a hinge mechanism is known. Among hinge mechanisms, there are those in which the torque during rotation is variable.

[0003] For example, FIG. 1 of Patent Document 1 describes a hinge mechanism including a shaft 10, a first bracket 13 attached to one end of the shaft 10, and a second bracket 17 fixed to the other end of the shaft 10. Flat portions 11 and 12 are provided on the outer peripheral surface of the one end side of the shaft 10, and the first bracket 13 is provided with a spring portion 16 that is rotatably attached to the one end of the shaft 10 and is elastically contactable with the flat portions 11 and 12.

[0004] In the hinge mechanism of Patent Document 1, as shown in FIGS. 2(a) and 2(b) of the same document, when the spring portion 16 overlaps either of the flat portions 11 and 12, the torque for rotating the second bracket 17 with respect to the first bracket 13 becomes small. On the other hand, as shown in FIGS. 2(b) and 2(c) of the same document, when the spring portion 16 does not overlap either of the flat portions 11 and 12, the elastic force of the spring portion 16 is applied to the shaft 10, so the torque for rotating the second bracket 17 with respect to the first bracket 13 becomes large.

[0005] In addition, Patent Document 2, FIG. 10 shows a damper device for a hinge mechanism, which is composed of a case 12, a shaft 13 rotatably accommodated in the case 12, a valve body 15 provided between the case 12 and the shaft 13, and a viscous fluid filled inside the case 12. The case 12 has a pair of support portions 12a, 12a, and the shaft 13 has a pair of blade portions 13a, 13b. Substantially V-shaped grooves 13c, 13c are formed at the tip portions of the blade portions 13a, 13b. The valve body 15 is provided with substantially V-shaped protrusions 15a, 15a. The protrusions 15a, 15a are inserted into the grooves 13c, 13c. Although a concave portion 15c is provided on one inclined surface 15b of the protrusion 15a, no concave portion is provided on the opposite inclined surface 15b'.

[0006] In the damper device (hinge mechanism) of Patent Document 2, as shown in FIG. 10(a) of the same document, when the shaft 13 rotates clockwise (direction B) with respect to the case 12, although the inclined surface 15b' and the inclined surface 13d' come into contact with each other, since no concave portion is provided on the inclined surface 15b', a flow path through which the viscous fluid can freely pass is not formed between chamber A and chamber B. Therefore, the minute gap between the support portion 12a and the shaft 13 serves as an orifice, and a braking function is exerted (the torque increases). On the other hand, as shown in FIG. 10(b) of the same document, when the shaft 13 rotates counterclockwise (direction A) with respect to the case 12, the inclined surface 15b and the inclined surface 13d come into contact with each other. At this time, since the concave portion 15c is provided on the inclined surface 15b, a flow path for allowing the viscous fluid to freely pass between chamber A and the second chamber is formed. Therefore, for rotation in the A direction, the braking function is not exerted (the torque decreases).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the hinge mechanism of Patent Document 1, the torque does not change unless the second bracket 17 is rotated relative to the first bracket 13 within a specific range. Conversely, in order to change the torque, it is necessary to rotate the second bracket 17 relative to the first bracket 13 within a specific range. It is impossible with the hinge function of Patent Document 1 for an operator of the hinge mechanism to arbitrarily switch the torque. In addition, in the hinge mechanism of Patent Document 1, it is also impossible to provide a difference between the torque when the second bracket 17 is rotated to one side relative to the first bracket 13 and the torque when it is rotated to the other side.

[0009] On the other hand, in the hinge mechanism of Patent Document 2, a difference can be provided between the torque when the shaft 13 is rotated to one side (B direction) relative to the case 12 and the torque when it is rotated to the other side (A direction). However, it is also impossible for an operator of the hinge mechanism to arbitrarily switch the torque even in the hinge mechanism of Patent Document 2. In addition, since the hinge mechanism of Patent Document 2 is a precision part that requires high dimensional accuracy, there is also a problem that the manufacturing cost tends to be high.

[0010] The present invention has been made to solve the above problems, and provides a hinge mechanism capable of providing a difference in torque depending on the rotation direction and allowing an operator to arbitrarily switch the torque during rotation. Another object of the present invention is to provide such a hinge mechanism with a simple and low-cost structure.

Means for Solving the Problems

[0011] The above problems are solved by a shaft member, a plurality of lock springs made of a coil spring having an inner diameter smaller than the outer diameter of the shaft member and wound around the outer peripheral portion of the shaft member in an elastically expanded diameter state, a fixed member fixed in a non-movable state relative to the shaft member, a rotating member attached to the shaft member in a state that allows it to rotate relatively; a holding member having a fixed end holding portion for holding the fixed end of the lock spring and fixed in a state where it does not move relative to the rotating member; Equipped with When torque is applied to the rotating member in a direction in which the lock spring winds up (hereinafter referred to as the "tightening direction"), if the torque is below a specified value, the rotating member will not rotate in the tightening direction. If the torque exceeds the specified value, the lock spring will slip relative to the shaft member, and the rotating member will rotate in the tightening direction. When torque is applied to the rotating member in the direction opposite to the tightening direction (hereinafter referred to as the "loosening direction"), the lock spring slips relative to the shaft member, causing the rotating member to rotate in the loosening direction. The holding member is provided with a free end locking portion that can forcibly displace the free ends of the lock springs toward the loosened side for each lock spring to lock them, By switching between a locked state in which the free end is not locked to the free end locking part and an unlocked state in which the free end is locked to the free end locking part, it is possible to adjust the torque when rotating the rotating member relative to the fixed member. A spring lock hinge mechanism characterized by This is solved by providing

[0012] In the hinge mechanism of the present invention, when the free end of the lock spring is engaged with the free end engagement portion (when the free end is in the unlocked position), the lock spring expands in diameter and becomes loose (unlocked state) relative to the shaft member, so that the rotating member can be rotated in either direction relative to the fixed member with a small torque.

[0013] In contrast, when the free end of the lock spring is not engaged with the free end engagement portion (when the free end is in the locked position), the lock spring tightens the shaft member (locked state). Even in this locked state, as described below, if the lock spring is displaced in the loosening direction (i.e., if torque in the loosening direction is applied to the rotating member), even a relatively small torque will cause the lock spring to slip relative to the shaft member, allowing the rotating member to rotate in that direction (loosening direction). However, if the lock spring is displaced in the tightening direction (i.e., if torque in the tightening direction is applied to the rotating member), a torque exceeding a significantly large specified value must be applied in order for the lock spring to slip relative to the shaft member, and the rotating member cannot be rotated in that direction (tightening direction).

[0014] In this way, the hinge mechanism of the present invention can provide a difference in torque depending on the rotation direction. Hereinafter, among the rotation directions of the hinge mechanism, the direction in which the torque becomes large (high) may be referred to as the "high torque direction," and the direction in which the torque becomes small (low) may be referred to as the "low torque direction."

[0015] Furthermore, in the hinge mechanism of the present invention, the operator can select whether or not to lock the free end of the lock spring with the free end locking portion, allowing the operator to freely switch the torque during rotation regardless of the rotation angle, etc. Multiple lock springs are provided (multiple lock springs are arranged at predetermined intervals along the longitudinal direction of the shaft member), and a free end locking portion is provided for each lock spring. This allows the number of lock springs whose free ends are locked with the free end locking portion to be adjusted in multiple stages, and also allows the torque during rotation to be adjusted in multiple stages. Furthermore, the hinge mechanism of the present invention, which uses lock springs, does not require the precision required for the hinge mechanism of Patent Document 2. Additionally, the hinge mechanism of the present invention can reduce the number of parts, thereby reducing the manufacturing cost of the hinge mechanism.

[0016] Incidentally, in the hinge mechanism of the present invention, the terms "fixed" in the fixed member and "rotating" in the rotating member are used for convenience. As long as the fixed member and the rotating member rotate relative to each other, the rotation mode is not limited. That is, all of the modes in which the rotating member rotates relative to the stationary fixed member, the fixed member rotates relative to the stationary rotating member, and the rotating member rotates relative to the rotating fixed member are included in the technical scope of the hinge mechanism of the present invention.

[0017] However, in this case, if adjacent lock springs come into contact (interfere) with each other, the operation of the lock springs may become unstable, and there is a possibility that the desired operation cannot be performed on the hinge mechanism. Therefore, when the hinge mechanism of the present invention is provided with a plurality of lock springs, it is preferable to provide a partition between adjacent lock springs. This can prevent adjacent lock springs from interfering with each other.

[0018] Also, when the hinge mechanism of the present invention is provided with a plurality of lock springs, it is preferable that some of the plurality of lock springs are right-handed springs and the rest are left-handed springs. This makes it possible to reverse the high-torque direction (low-torque direction) itself. For example, if an even number of lock springs are used, half of them are right-handed springs and the other half are left-handed springs, it is possible to reverse the high-torque direction (reverse the low-torque direction) when all the right-handed springs are in the locked state and all the left-handed springs are in the unlocked state, and when all the right-handed springs are in the unlocked state and all the left-handed springs are in the locked state.

[0019] Furthermore, when the hinge mechanism of the present invention includes multiple locking springs, it is also preferable to provide a free-end connecting member that integrally connects the free ends of the multiple locking springs and a connecting member moving mechanism that moves the free-end connecting member relative to the retaining member. This allows the free ends of the multiple locking springs to be moved simultaneously, making it easier to operate the hinge mechanism. It also allows the free ends of the locking springs to be held at an intermediate position between the locked and unlocked positions, allowing for more precise torque adjustment. In addition, it also allows the free ends of the locking springs to be held at a position displaced toward the tightening side from the locked position, further increasing the torque (slip torque) when rotating the hinge mechanism. [Effects of the Invention]

[0020] As described above, the present invention makes it possible to provide a hinge mechanism that allows the torque to be varied depending on the rotation direction and that allows the operator to freely switch the torque during rotation.Furthermore, it is also possible to provide such a hinge mechanism with a simple and low-cost structure. [Brief explanation of the drawings]

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0022] The spring lock type hinge mechanism of the present invention will be specifically described with reference to the drawings. In the following, four embodiments (from the first embodiment to the fourth embodiment) will be taken as examples to describe the hinge mechanism of the present invention. However, these embodiments are merely preferred embodiments, and the technical scope of the hinge mechanism of the present invention is not limited to these embodiments. The hinge mechanism of the present invention can be appropriately modified within the scope that does not impair the gist of the invention.

[0023] 1. Spring Lock Type Hinge Mechanism of the First Embodiment First, the spring lock type hinge mechanism of the first embodiment will be described. FIG. 1 is a perspective view showing the spring lock type hinge mechanism of the first embodiment. FIG. 2 is a perspective view showing the disassembled state of the spring lock type hinge mechanism of the first embodiment. FIG. 3 is a plan view showing the spring lock type hinge of the first embodiment. FIG. 4 is a cross-sectional view of the spring lock type hinge mechanism of the first embodiment taken along X1-X1 in FIG. 3. FIG. 4(a) shows the state where the free end 22 of the lock spring 20 is in the locked position, and FIG. 4(b) shows the state where the free end 22 of the lock spring 20 is in the unlocked position.

[0024] 2, the hinge mechanism of the first embodiment includes an axis member 10, a lock spring 20, a fixed member 30, a rotating member 40, and a holding member 50, and connects the rotating member 40 to the fixed member 30 in a state where the rotating member 40 can rotate relatively to the fixed member 30. As already mentioned, in the hinge mechanism of the present invention, the manner in which the fixed member 30 and the rotating member 40 rotate is not limited, but for the sake of convenience, the following description will be given taking as an example a case in which the rotating member 40 rotates relative to the immovable fixed member 30.

[0025] The shaft member 10 is a cylindrical or columnar member that defines the rotation center of the hinge mechanism. The rotation member 40 rotates relative to the fixed member 30 around the shaft member 10.

[0026] The lock spring 20 is a coil spring with an inner diameter that is several percent (for example, about 2 to 5%) smaller than the outer diameter of the shaft member 10. This lock spring 20 is wound (fitted) around the outer periphery of the shaft member 10 in a state in which it is elastically expanded in diameter. Although only one lock spring 20 may be fitted around the shaft member 10, in the hinge mechanism of the first embodiment, four lock springs 20 are fitted around the shaft member 10 at predetermined intervals in the longitudinal direction.

[0027] The fixing member 30 is fixed so as not to move relative to the shaft member 10. In the hinge mechanism of the first embodiment, the fixing member 30 has a configuration in which a pair of left and right side plate portions 31, 31 are connected by a band-shaped portion 32. Each of the side plate portions 31, 31 is provided with a through hole for passing the shaft member 10 therethrough, and is fixed to the shaft member 10 at the through hole. The fixing member 30 and the shaft member 10 are integrated by caulking, but other joining methods such as welding or bolting may also be used. The band-shaped portion 32 is provided with a bolt hole for passing a bolt 60 therethrough.

[0028] The rotating member 40 is attached to the shaft member 10 in a relatively rotatable state. In the hinge mechanism of the first embodiment, the rotating member 40 has a form in which a pair of left and right side plate portions 41, 41 are connected by a belt-like portion 42. Through holes for passing the shaft member 10 are provided in the respective side plate portions 41, 41, and the shaft member 10 is pivotally supported at the portions of these through holes. Bolt holes for passing bolts 60 are provided in the belt-like portion 42.

[0029] The holding member 50 is a member having a fixed-end holding portion 51 for holding one end (fixed end 21) of the locking spring 20. A free-end locking portion 52 that can lock the free end 22 of the locking spring 20 in a displaced state toward the loosening side is also provided on the holding member 50. In the hinge mechanism of the first embodiment, the rotating member 40 is formed in a cylindrical shape so as to be able to enclose the shaft member 10 and the locking spring 20. This holding member 50 has a structure that can be divided into two semi-cylindrical members (upper holding member 50a and lower holding member 50b). Plate-like protruding pieces 53, 53 are provided on each of the upper holding member 50a and the lower holding member 50b. Bolt holes for passing bolts 60 are provided in the respective protruding pieces 53, 53. By passing the bolts 60 through the bolt holes of the protruding pieces 53, 53 in the holding member 50 and the bolt holes of the belt-like portion 42 in the rotating member 40, the upper holding member 50a and the lower holding member 50b are integrated, and the holding member 50 is integrated with the rotating member 40.

[0030] The fixed-end holding portion 51 is provided in a groove shape at the boundary between the upper holding member 50a and the lower holding member 50b. Since the number of locking springs 20 is four, the fixed-end holding portion 51 may be provided at four locations, but in the hinge mechanism of the first embodiment, it is provided at eight locations. This is to enable corresponding even if the positional relationship between the fixed end 21 and the free end 22 of each locking spring 20 is reversed.

[0031] As shown in FIG. 3, the free end locking portion 52 is provided at one end of a free end passage 54, which is an elongated hole formed along the circumferential direction of the cylinder. Because there are four lock springs 20, the free end passages 54 and free end locking portions 52 need only be provided at four locations. However, in the hinge mechanism of the first embodiment, as shown in FIG. 4, the free end passages 54 and free end locking portions 52 are provided at four locations on the upper holding member 50a, as well as at four locations on the lower holding member 50b. The free end passages 54 and free end locking portions 52 of the upper holding member 50a and the free end passages 54 and free end locking portions 52 of the lower holding member 50b are arranged symmetrically from top to bottom. This is to accommodate both right-handed and left-handed winding locking springs, which can be used as lock springs 20.

[0032] As shown in FIG. 4(a), when the lock spring 20 in this hinge mechanism has its free end 22 in the locked position (approximately the middle position of the free end passage 54), the lock spring 20 is in a locked state in which it tightens the shaft member 10. Even in this locked state, if counterclockwise torque (torque in a direction that causes the rotating member 40 to rotate counterclockwise about the center line L1 in FIG. 4(a)) is applied to the rotating member 40, the retaining member 50, which rotates together with the rotating member 40, also displaces the fixed end 21 of the lock spring 20 in the counterclockwise direction (in the direction that pushes the fixed end 21 in), causing the diameter of the lock spring 20 to expand slightly and the lock spring 20 to become loose relative to the shaft member 10. Therefore, even if the torque is relatively small, the lock spring 20 slips relative to the shaft member 10, and the rotating member 40 rotates in that direction. Thus, among the rotation directions of the rotating member 40, the direction in which the lock spring 20 is loosened is called the “loosening direction.” The torque required to rotate the rotating member 40 at this time (a value assuming there is only one lock spring 20; the same applies below) is defined as T1.

[0033] On the other hand, when the locking spring 20 is in the locked state, if a clockwise torque (the torque in the direction in which the rotating member 40 rotates clockwise about the center line L1 in FIG. 4(a)) is applied to the rotating member 40, the fixed end 21 of the locking spring 20 is also displaced in the clockwise direction (the direction in which the fixed end 21 is pulled) by the holding member 50 that rotates together with the rotating member 40. Therefore, the locking spring 20 contracts in diameter, and the locking spring 20 is in a state of strongly clamping the shaft member 10. For this reason, to the extent that the above torque T1 is applied, the locking spring 20 does not slip with respect to the shaft member 10, and the rotating member 40 cannot be rotated. Only when a torque T2 exceeding the torque T1 (the value when it is assumed that there is only one locking spring 20; the same applies hereinafter) is applied, the locking spring 20 slips with respect to the shaft member 10, and the rotating member 40 rotates in that direction. Thus, among the rotation directions of the rotating member 40, the direction in which the locking spring 20 clamps the shaft member 10 is referred to as the "clamping direction".

[0034] Thus, when the locking spring 20 is in the locked state, the torque T2 when rotating the rotating member 40 in the clamping direction is greater than the torque T1 when rotating the rotating member 40 in the loosening direction. In other words, it is heavier (the resistance force is greater) when rotating the rotating member 40 in the clamping direction than when rotating the rotating member 40 in the loosening direction.

[0035] On the other hand, as shown in FIG. 4(b), when the free end 22 of the locking spring 20 is displaced in the direction of arrow A1 and locked to the free end locking portion 52 (held at the unlocking position), the locking spring 20 expands in diameter, and the state becomes loose with respect to the shaft member 10 (unlocked state). For this reason, the rotating member 40 can rotate in a substantially free state in both the clamping direction and the loosening direction by applying only a torque T3 that is much smaller than the above torque T1.

[0036] In this regard, in the hinge mechanism of the first embodiment, four locking springs 20 are provided, and the free ends 22 of the respective locking springs 20 can be operated separately (it is possible to separately select whether to set the free end 22 to the locked position or the unlocked position).

[0037] For this reason, as shown in Figure 3, when the free ends 22 of all four lock springs 20 are in the locked position (all four lock springs 20 are in the locked state), a torque of 4 x T1 must be applied to rotate them in the loosening direction, and a torque of 4 x T2 must be applied to rotate them in the tightening direction. In contrast, when three lock springs 20 are in the locked state but the free end 22 of one lock spring 20 is in the unlocked position (one lock spring 20 is in the unlocked state), a torque of 3 x T1 must be applied to rotate them in the loosening direction, and a torque of 3 x T2 must be applied to rotate them in the tightening direction. By further increasing the number of lock springs 20 in the unlocked state, the above torque can be gradually reduced.

[0038] Incidentally, when multiple lock springs 20 are used, as in the hinge mechanism of the first embodiment, if adjacent lock springs 20 come into contact (interfere) with each other, the operation of the lock springs 20 may become unstable. For this reason, in the hinge mechanism of the first embodiment, as shown in FIG. 2, an inner flange-shaped partition 55 is provided on the inner periphery of the holding member 50. This partition 55 is provided not only on the lower holding member 50b but also on the upper holding member 50a, approximately symmetrically in the vertical direction. This prevents adjacent lock springs 20 from interfering with each other, thereby stabilizing the operation of the lock springs 20.

[0039] 2. Second embodiment of spring lock hinge mechanism Next, a spring lock hinge mechanism of a second embodiment will be described. The hinge mechanism of the second embodiment will be described focusing on the configuration that is different from the hinge mechanism of the first embodiment. Configurations of the hinge mechanism of the second embodiment that are not specifically mentioned can be substantially the same as those described for the hinge mechanism of the first embodiment.

[0040] Figure 5 is a plan view of a spring lock hinge mechanism of the second embodiment. While the hinge mechanism of the first embodiment (Figure 2) uses four lock springs 20, the hinge mechanism of the second embodiment uses five lock springs 20, as shown in Figure 5. Therefore, free end passages 54 and free end engaging portions 52 are also provided in five locations on the upper holding member 50a. This makes it possible to adjust the torque when rotating the hinge mechanism in multiple stages over a wider range.

[0041] For example, in FIG. 5( a), all five lock springs 20 are in the locked state. In this state, the hinge mechanism is in a "maximum torque" state in which the rotational torque is large. In FIG. 5( b), three of the five lock springs 20 are in the locked state, and the remaining two lock springs 20 are in the unlocked state. In this state, the hinge mechanism is in a "medium torque" state in which the rotational torque is medium. In FIG. 5( c), only one of the five lock springs 20 is in the locked state, and the remaining four lock springs 20 are in the unlocked state. In this state, the hinge mechanism is in a "low torque" state in which the rotational torque is small. In addition to this, the hinge mechanism can also be in a "high torque" state in which four lock springs 20 are in the locked state and one lock spring 20 is in the unlocked state, or a "minimum torque" state (free state) in which all five lock springs 20 are in the unlocked state.

[0042] In this way, by increasing the number of lock springs 20, the torque when rotating the hinge mechanism can be adjusted in multiple stages over a wider range. When multiple lock springs 20 are used, the number of lock springs 20 is typically in the range of 3 to 30, and preferably in the range of 4 to 10. Here, if only the torque when the lock spring 20 is in the locked state (lock torque) is to be increased, this can be achieved by increasing the wire diameter of the lock spring 20 or the number of windings. However, in this case, the outer diameter of the lock spring 20 increases, which increases the dimension around the axis of the hinge mechanism (the radial dimension about the center line L1). In addition, the increased lock torque may be concentrated on the fixed end 21 of the lock spring 20, which may cause damage to the lock spring 20 near the fixed end 21. In this regard, by increasing the number of lock springs 20, it is possible to increase the lock torque while suppressing an increase in the dimension around the shaft diameter of the hinge mechanism and damage to the lock springs 20.

[0043] 3. Third embodiment of spring lock hinge mechanism Next, a spring lock hinge mechanism of a third embodiment will be described. The hinge mechanism of the third embodiment will be described focusing on the configuration that is different from the hinge mechanism of the first embodiment. Configurations of the hinge mechanism of the third embodiment that are not specifically mentioned can be substantially the same as those described for the hinge mechanisms of the first and second embodiments.

[0044] Figure 6 is a plan view showing the interior of a spring lock hinge mechanism of a third embodiment. In the hinge mechanism of the first embodiment (Figure 2), all of the multiple lock springs 20 were of the same type (left-handed springs), but in the hinge mechanism of the third embodiment, as shown in Figure 6, the lock springs 20 are a mixture of left-handed springs 20a and right-handed springs 20b. Specifically, of the four lock springs 20 shown in Figure 6, two lock springs 20 on both the left and right sides are right-handed springs 20b, and two lock springs 20 on the inside (center) are left-handed springs 20a.

[0045] The free end 22 of the left-handed spring 20a passes through the free end passage 54 and the free end locking portion 52 on the upper holding member 50a side, and the free end 22 of the right-handed spring 20b passes through the free end passage 54 and the free end locking portion 52 of the lower holding member 50b (see FIG. 2). Since the free end passage 54 and the free end locking portion 52 on the upper holding member 50a side and the free end passage 54 and the free end locking portion 52 on the lower holding member 50b side are formed symmetrically up and down, in this way, either the left-handed spring 20a or the right-handed spring 20b can be used. In addition, in order to correspond to both the left-handed spring 20a and the right-handed spring 20b, it is not always necessary to make the free end passage 54 and the free end locking portion 52 symmetrical up and down with the upper holding member 50a and the lower holding member 50b. For example, even if the free end passage 54 and the free end locking portion 52 have the same shape with the upper holding member 50a and the lower holding member 50b, it is possible to correspond to both the left-handed spring 20a and the right-handed spring 20b.

[0046] In this way, by mixing the left-handed spring 20a and the right-handed spring 20b as the lock spring 20, not only can the magnitude of the torque when rotating the hinge mechanism be adjusted, but it is also possible to reverse the high torque direction (the direction in which the torque increases when rotating). For example, as shown in FIG. 6(a), when the right-handed spring 20b is in the locked state and the left-handed spring 20a is in the unlocked state, the tightening direction of the right-handed spring 20b (the loosening direction of the left-handed spring 20a) becomes the high torque direction, whereas, as shown in FIG. 6(b), when the right-handed spring 20b is in the unlocked state and the left-handed spring 20a is in the locked state, the loosening direction of the right-handed spring 20b (the tightening direction of the left-handed spring 20a) becomes the high torque direction.

[0047] 4. Spring Lock-Type Hinge Mechanism of the Fourth Embodiment Finally, the spring lock-type hinge mechanism of the fourth embodiment will be described. Regarding the hinge mechanism of the fourth embodiment, the description will be limited to the configuration different from that of the hinge mechanism of the first embodiment. For the configuration not particularly mentioned in the hinge mechanism of the fourth embodiment, a configuration substantially the same as that described in the hinge mechanisms of the first embodiment, the second embodiment, and the third embodiment can be adopted.

[0048] Figure 7 is a plan view showing the spring lock type hinge mechanism of the fourth embodiment. As shown in FIG. 7, the hinge mechanism of the fourth embodiment includes a free end connecting member 70 and a connecting member moving mechanism 80. The free end connecting member 70 is a plate-like member that integrally connects the free ends 22 of a plurality of locking springs 20. The connecting member moving mechanism 80 moves the free end connecting member 70 with respect to the holding member 50.

[0049] The structure of the connecting member moving mechanism 80 is not particularly limited. However, in the hinge mechanism of the fourth embodiment, a bolt screwed into the free end connecting member 70 functions as the connecting member moving mechanism 80. When the bolt 80 is rotated to one side, the free end connecting member 70 moves in the direction of arrow A2 in FIG. 7, and the free ends 22 of the respective locking springs 20 are moved in the tightening direction. On the other hand, when the bolt 80 is rotated to the other side, the free end connecting member 70 moves in the direction opposite to arrow A2, and the free ends 22 of the respective locking springs 20 are moved in the loosening direction.

[0050] Thus, by providing the free end connecting member 70 and the connecting member moving mechanism 80, the free ends of the plurality of locking springs 20 can be moved simultaneously, and the operation of the hinge mechanism can be easily performed. In addition, the free end 22 of the locking spring 20 can be held at an intermediate position between the locked position and the unlocked position, and the torque can be adjusted more finely. Furthermore, the free end 22 of the locking spring 20 can be held at a position displaced further toward the tightening side than the locked position shown in FIG. 7, and the torque (slip torque) when rotating the hinge mechanism can be further increased.

[0051] 5. Applications The hinge mechanism of the present invention is not particularly limited in its application and can be used in various applications. However, since the hinge mechanism of the present invention has the above characteristics, it can be preferably adopted in applications where it is necessary to provide a difference in torque depending on the rotation direction, or in applications where the operator needs to adjust the torque during rotation. Examples of such applications include furniture such as angle-adjustable beds and chairs.

Explanation of Reference Numerals

[0052] 10 Shaft member 20 Lock spring 20a Left-handed spring 20b Right-handed spring 21 Fixed end 22 Free end 30 Fixed member 31 Side plate portion 32 Band portion 40 Rotating member 41 Side plate portion 42 Band portion 50 Holding member 50a Upper holding member 50b Lower holding member 51 Fixed end holding portion 52 Free end locking portion 53 Projection portion 54 Free end passage 55 Partition portion 60 Bolt 70 Free end connecting member 80 Connecting member moving mechanism

Claims

1. A shaft member, a plurality of lock springs each formed of a coil spring having an inner diameter smaller than the outer diameter of the shaft member and wound around the outer peripheral portion of the shaft member in an elastically expanded diameter state, a fixed member fixed in a state of not moving relative to the shaft member, a rotating member attached in a state of being relatively rotatable with respect to the shaft member, a holding member having a fixed end holding portion for holding the fixed end of the lock spring and fixed in a state of not moving relative to the rotating member, comprising: When a torque in the winding-up direction (hereinafter referred to as the "tightening direction") of the lock spring is applied to the rotating member, if the torque is equal to or less than a specified value, the rotating member does not rotate in the tightening direction, and if the torque exceeds the specified value, the lock spring slips relative to the shaft member while the rotating member rotates in the tightening direction, while having a structure in which when a torque in the direction opposite to the tightening direction (hereinafter referred to as the "loosening direction") is applied to the rotating member, the lock spring slips relative to the shaft member and the rotating member rotates in the loosening direction, a free end locking portion capable of forcibly displacing the free end of the lock spring to the loosening side for each lock spring is provided on the holding member, By switching between a locked state in which the free end is not locked to the free end locking portion and an unlocked state in which the free end is locked to the free end locking portion, the torque when the rotating member is relatively rotated with respect to the fixed member can be adjusted. A spring lock type hinge mechanism characterized by the above.

2. A partition portion is provided between adjacent lock springs. The spring lock type hinge mechanism according to claim 1.

3. The spring lock type hinge mechanism according to claim 1, wherein some of the plurality of lock springs are right-handed springs and the rest are left-handed springs.

4. A free end connecting member for integrally connecting the free ends of the plurality of lock springs, and a connecting member moving mechanism for moving the free end connecting member relative to the holding member. The lock type hinge mechanism according to claim 1, comprising:

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