JP2000296758A - Belt fastening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily fix an automobile young-person safety belt to a seat of an automobile using a seat belt provided in the automobile. SOLUTION: A seat belt 3 has a first belt part 4 and a second belt part 5 arranged in the bottom of a belt fastening device 200 so as to be restricted its position and the second belt 5 is fastened by a belt fastening device 100. The length of the seat belt 3 is adjusted by fastening the second belt part 5 of the seat belt 3 upward in an arrow P direction so that the second belt part 5 of the seat belt 3 is fixed by a belt fastening device 100 in its position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt tightening device, and more particularly, to a structure of a belt tightening device capable of easily performing a belt tightening operation.

[0002]

2. Description of the Related Art In recent years, there has been increasing awareness of improving the safety of automobiles, and when a young child who grows into a newborn, an infant, a toddler or a schoolchild is put on the automobile, the safety of the young person in the automobile is increased. As a device for ensuring safety, a child safety seat for an automobile has been developed.

This child safety seat for automobiles is generally
The vehicle is fixed to a vehicle seat using a seat belt provided in the vehicle. Therefore, it is important to securely attach the child safety seat to the vehicle.

[0004] Therefore, as a method of securely fixing a child safety seat for a vehicle to a vehicle seat using a seat belt, a child safety seat for a vehicle using a belt clip disclosed in Japanese Utility Model Laid-Open Publication No. 7-31522 is disclosed. There is a method of fixing.

Hereinafter, referring to FIG.
A method of fixing a child safety seat for an automobile disclosed in Japanese Patent Publication No. 522 will be described.

The child safety seat 2 for an automobile has a seat 30A.
When the child safety seat 2 for a vehicle is to be fixed to the original seat of the vehicle using the belt clip 20 having the shape shown in FIG.
The tongue plate 6 of the point type seat belt 3 is used as a base 30B.
The first belt portion 4 and the second belt portion 5 that pass over the mounting surface 8 of the
Is positioned on the mounting surface 8 and the tongue plate 6 is
The vehicle safety seat 2 is fixed to the vehicle seat by being connected to the receptacle provided in the vehicle.

At this time, the length of the seat belt 3 is adjusted by adjusting both the first belt portion 4 and the second belt portion 5 of the seat belt 3 using the belt clip 20, so that the child safety seat 2 for an automobile is provided. Is securely fixed to a car seat.

[0008]

However, in fixing the child safety seat 2 for an automobile using the belt clip 20, it is necessary to adjust the length of the seat belt 3 using the belt clip 20 in advance. If the belt clip 20 is lost, the child safety seat 2 for a vehicle cannot be fixed.

Accordingly, an object of the present invention is to provide a belt tightening device capable of easily adjusting the length of a belt, and in particular, to a vehicle using a seat belt provided with a vehicle safety seat for a child under vehicle. An object of the present invention is to provide a belt fastening device that can be fixed to a seat.

[0010]

In one aspect of the belt tightening device according to the present invention, the belt is sandwiched together with the main body to allow the belt to move in a first longitudinal direction. A belt tightening device including a tightening unit that does not allow movement in a second direction opposite to the first direction, wherein the tightening unit is rotatably supported with respect to the main body. And a lock member that allows the belt to slide in the first direction and prevents the belt from sliding in the second direction.

In another aspect of the belt tightening device according to the present invention, the belt is sandwiched together with the main body to allow movement of the belt in a first longitudinal direction. A belt tightening device comprising tightening means that does not allow movement in a second direction opposite to the second direction, wherein the tightening means is arranged in a direction intersecting a direction in which the belt moves. A housing member having an end side rotatably mounted on the main body and the other end side capable of selecting between an open state and a closed state with respect to the main body; and the housing member for sandwiching the belt with the main body. At a position facing the main body so as to be rotatable along the direction in which the belt moves, allowing the belt to slide in the first direction, and sliding in the second direction. B to prevent And a click member.

According to the belt tightening device, the length of the belt can be adjusted after the belt is sandwiched. Further, by providing the housing member with a lock member that is rotatably mounted along the direction in which the belt moves, the belt is allowed to move in the first direction in the longitudinal direction, and is opposite to the first direction. Can be realized without allowing movement in the second direction. As a result, the belt can be easily tightened,
On the other hand, it is possible to easily perform the operation of releasing the tightening of the belt.

In order to implement the above-mentioned invention in a more preferable state, the following configuration is adopted. The cross section of the lock member along the direction in which the belt extends is such that a first portion longer than a distance from a rotation center to the main body is provided on the first direction side, and the rotation portion is provided on the second direction side. A second portion shorter than the distance from the moving center to the main body.

The lock member has a rotation support shaft at both ends, and the rotation support shaft is supported by an elongated hole along the direction in which the belt moves.

[0015] Further, the belt is allowed to slide in the first direction on the contact surface of the belt between the first portion and the second portion, and the belt is allowed to slide in the first direction. An uneven surface is provided to prevent sliding on the surface.

The main body includes a concave surface capable of receiving the lock member. By adopting the above configuration, the belt can be reliably moved along the lock member when the belt is fastened, so that the work of fastening the belt by the lock member can be reliably performed.

A child safety seat for a vehicle according to the present invention is a child safety seat for a vehicle which is fixed to a seat of the vehicle using a seat belt attached to the vehicle, wherein the child safety seat for a vehicle is provided. When fixing the seat to the vehicle seat using the seatbelt, the seatbelt is sandwiched together with the main body of the vehicle child safety seat in order to adjust the degree of tightening of the seatbelt, and The first in the longitudinal direction of the belt
And a belt fastening device having fastening means that does not allow movement in a second direction opposite to the first direction.

According to this child safety seat for an automobile, the seat belt can be tightened in the second belt portion of the seat belt after the seat belt is fixed, and the vehicle having the child safety seat for an automobile can be realized. It is possible to easily attach the camera to the camera.

The direction in which the seat belt tends to extend (the direction in which the state of securing the child safety seat for the vehicle to the vehicle seat is loosened) is always the direction in which the fastening and fastening of the seat belt by the lock member work. Therefore, the state in which the child safety seat for the vehicle is fixed to the vehicle seat is not released, and the mechanism is effective for safety.

In order to carry out the above-mentioned invention in a more preferable state, the following configuration is adopted. The seat belt includes a first belt portion extending from a lower side of a seat of the vehicle, and a first belt portion extending upward from a tongue plate removably fixed to a receptacle of a buckle provided on the vehicle side. A three-point seat belt having two belt portions, wherein the child safety seat for a vehicle has a mounting surface through which the first belt portion of the seat belt passes, and the belt fastening device includes the mounting member. It is arranged in the vicinity of a surface and on the side of the child safety seat for an automobile separated from the tongue plate, and is provided so as to sandwich and fix the second belt portion.

The mounting surface has a concave portion for receiving the seat belt. Further, the belt tightening device has a housing that can be opened and closed, and a tip portion thereof is
It is provided so as to protrude on the mounting surface.

Further, the belt fastening device is provided on both sides of a main body of the child safety seat for an automobile.

By adopting the above configuration, it is possible to prevent a seat belt used for a child safety seat for an automobile from dropping off from a mounting surface, thereby providing a mechanism effective for safety.

Preferably, the child safety seat for a vehicle has a seat and a base, and the belt fastening device is provided on the base. This makes it possible to securely hold the child safety seat for an automobile using the seat belt.

Further, in order to carry out the above-mentioned invention in a more preferable state, the following configuration is adopted. Of the components of the force applied to the belt fastening device from the seat belt, a component of a force that is directed substantially upward is absorbed, and only the force in the sliding direction of the seat belt is applied to the belt fastening device. Further comprising an auxiliary device for performing the operation.

By employing this configuration, only the force in the sliding direction of the seat belt is applied to the belt fastening device, so that the seat belt is securely fastened by the belt fastening device and the force is applied to the seat belt. It is possible to improve the safety of the child safety seat for a car when the vehicle is added.

In a more preferred form, the seat belt includes a first belt portion extending from a lower side of a seat of the vehicle, and a tongue plate detachably fixed to a receptacle of a buckle provided on the vehicle side. And a second belt portion extending upward from a seat of the vehicle from above. The child safety seat for a vehicle has a mounting surface for passing the first belt portion of the seat belt. The belt tightening device is disposed near the mounting surface and on a side of the vehicle-use child safety seat away from the tongue plate, and is provided so as to sandwich and fix the second belt portion. And an auxiliary device having a guide portion for passing the second belt portion substantially upward from the belt fastening device.

Preferably, the auxiliary device is provided such that the guide portion is located below a portion where the second belt portion is sandwiched by the belt tightening device.

By adopting this configuration, it becomes possible for the auxiliary device to reliably absorb the upward component of the force applied from the seat belt to the belt fastening device. .

Preferably, the guide portion is a second guide portion.
There is a cut for sliding the belt part. This makes it possible to easily hang the second belt portion on the auxiliary device.

Preferably, the child safety seat for a vehicle has a seat and a base, and the belt fastening device and the auxiliary device are provided on the base. Also,
Preferably, the belt tightening device is provided on an upper surface of the base, and the auxiliary device is provided on a side surface of the base. More preferably, the belt tightening device is provided on both sides of an upper surface of the base, and the auxiliary device is provided on both sides of a side surface of the base.

Thus, it is possible to securely fasten the seat belt using the belt fastening device and to hold the child safety seat for an automobile.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a belt fastening device according to an embodiment of the present invention applied to a child safety seat for an automobile; FIG. FIG. 1 is an overall perspective view, and FIGS. 2 and 3 are cross-sectional views showing the structure of the belt fastening device, corresponding to the cross section taken along line XX ′ in FIG. 1, and FIGS. FIG. 4 is a cross-sectional view illustrating a tightening state of the belt using the tightening device in a step order, and corresponds to a cross section taken along line YY ′ in FIG. 3.
FIG. 11 is an overall perspective view showing a structure using a belt hook (described later). (Overall Configuration) First, referring to FIG. 1, a child safety seat 2 for an automobile is provided with a seat 30A. And a base 30B (FIG. 1).
2), near the rear end of the upper surface 31 of the base 30B of the child safety seat for an automobile, for disposing the first belt portion 4 and the second belt portion 5 overlapping the two seat belts 3. A groove-shaped mounting surface 32 is provided.

The seat belt 3 has a tongue plate 6
It is locked by being inserted into the buckle 7. Belt fastening devices 100 and 200 according to the present embodiment are provided on both sides of the upper surface 31 on the rear side of the mounting surface 32.

As shown in FIG. 1, the seat belt 3 includes a first belt part 4 and a second belt part
By being arranged below 00, its position is restricted. This makes it possible to prevent the first belt portion 4 and the second belt portion 5 of the seat belt 3 from falling off from the mounting surface 32. Further, the second belt portion 5 is fastened to the belt fastening device 100.

The length of the seat belt 3 is adjusted by tightening the second belt portion 5 of the seat belt 3 in the direction of the arrow P1 in the figure, so that the second belt portion 5 of the seat belt 3 is positioned at that position.
Is fixed by the belt fastening device 100.

Therefore, the belt tightening device 200 disclosed in FIG. 1 is used for restraining the positions of the first belt portion 4 and the second belt portion 5 of the seat belt 3. When the seat belt 3 is fixed to the opposite seat, the length of the seat belt 3 is adjusted by the belt fastening device 200, and the first position of the seat belt 3 is adjusted by the belt fastening device 100.
The positions of the belt part 4 and the second belt part 5 are restricted.

(Structure of the belt fastening devices 100 and 200)
Hereinafter, a detailed structure of the belt fastening devices 100 and 200 will be described with reference to FIGS. 2 and 3. Further, since the structures of the belt tightening devices 100 and 200 are the same except that they are symmetrical structures, only the structure of the belt tightening device 100 will be described here. 2 and 3 are cross-sectional views taken along line XX 'in FIG.

First, referring to FIGS. 2 and 3, the belt fastening device 100 according to the present embodiment sandwiches the second belt portion 5 of the seat belt 3 together with the main body portion 31, and Movement in the longitudinal direction (P1 direction in FIG. 1) is allowed, and the opposite direction (P2 in FIG. 1)
(Direction) is not allowed.

The belt fastening device 100 is a seat belt 3
And a housing member 100A arranged in a direction intersecting the direction in which the second belt portion 5 moves. this,
The housing member 100A includes a housing body 101,
The rear end portion 106 side of the housing main body 101 is rotatably mounted on the upper surface 31 of the base 30B of the child safety seat for an automobile using a shaft 33, and the front end portion 105 is provided so as to protrude from the mounting surface 32. Can be Further, an opening / closing mechanism that allows the distal end portion 105 side of the housing main body 101 to select an open state or a closed state with respect to the main body 31 is employed.

The opening / closing mechanism includes an adjusting lever 102 provided on the end portion 105 side, and an adjusting lever 102
A hook member 104 connected to the lock shaft 34 provided on the upper surface 31 and having a substantially U-shaped cross section for applying an elastic force to the hook member 104 is provided. 2 shows a state in which the engagement of the hook member 104 with the lock shaft 34 is open, and the state shown in FIG. 3 shows a state in which the engagement of the hook member 104 with the lock shaft 34 is closed. FIG.

At the position facing the upper surface 31 of the housing body 101, the second belt portion 5 of the seat belt 3 is sandwiched together with the upper surface 31 so that the second belt portion 5 of the seat belt 3 moves together with the upper surface 31 in the moving direction. A lock member 107 is provided so as to be rotatable.

Referring to FIG. 3 and FIG.
Reference numeral 07 denotes a rotation support shaft 108 provided at both ends, and the rotation support shaft 108 is supported by a bearing hole 109 a provided in a bearing portion 109 provided in the housing body 101.
The bearing hole 109a has a long slot shape along the direction in which the second belt portion 5 of the seat belt 3 moves.

Referring to FIG. 4 and FIG.
07 has a first portion 107b on the P1 direction side,
It has a substantially fan-shaped cross section having a second portion 107c on the P2 direction side.

Length (L1) from the center of rotation support shaft 108, which is the center of rotation, to the tip of first portion 107b
Is provided longer than the shortest distance (L3) from the center of the rotation support shaft 108 to the upper surface 31 and is a length from the center of the rotation support shaft 108, which is the rotation center, to the tip end of the second portion 107c. (L2) is provided to be shorter than the shortest distance from the center of the rotation support shaft 108 to the upper surface 31 (L3: the distance from the center of the rotation support shaft 108 to Pmin).

A saw-toothed uneven surface 107a is provided between the tip of the first portion 107b and the tip of the second portion 107c. The sawtooth-shaped tip of the uneven surface 107a is formed so as to flow toward the P1 direction.

On the other hand, a concave portion capable of receiving the lock member 107 is provided on the upper surface 31, and P is higher than Pmin.
On the one direction side, the distance from the center of the rotation support shaft 108 is constituted by a curved surface 31a longer than (L1),
On the P2 direction side of Pmin, the rotation support shaft 10
8, the distance from the center is shorter than (L1), and (L1)
It is composed of a curved surface 31b longer than 2). A step 31c is provided on the curved surface 31b in the direction P2.

Further, a surface of the housing body 101 on which the lock member 107 is provided is provided with a surface in contact with the first portion 107b in order to restrict the movement of the lock member 107.
Inner surface 101 having a surface abutting on second portion 107c
a is formed. Further, convex portions 101b for pressing down the second belt portion 5 of the seat belt 3 downward are provided on the P1 direction side and the P2 direction side of the inner surface 107a.

(Tightening Principle) Next, the principle of tightening the second belt portion 5 of the seat belt 3 using the belt tightening device 100 having the above configuration will be described with reference to FIGS. 4 and 6 to 10. I do.

FIG. 4 shows a state where the second belt portion 5 of the seat belt 3 is pulled in the direction P1.
In this state, the lock member 107 is located in the P1 direction,
A sufficient gap is formed between the lock member 107 and the curved surface 31a to allow the second belt portion 5 of the seat belt 3 to pass.

The uneven surface 107a of the lock member 107
Is provided so as to flow in the P1 direction,
The movement of the second belt portion 5 of the seat belt 3 in the P1 direction is not prevented. By this operation, the seat belt 3
Can be tightened to the required length.

Next, referring to FIGS. 6 to 9, the P of the second belt portion 5 of the seat belt 3 tightened by the required length will be described.
When the tightening force in one direction is released, a force temporarily returning in the P2 direction is generated in the second belt portion 5 of the seat belt 3. At this time, the uneven surface 107a of the lock member 107 is hooked on the second belt portion 5 and moves in the direction P2 (the state shown in FIG. 6 → FIG. 7).

Further, the second belt portion 5 of the seat belt 3
Moves in the direction P2, the lock member 107 starts to rotate counterclockwise (the state shown in FIGS. 7 to 8). Thereafter, when the second belt portion 5 of the seat belt 3 further moves in the P2 direction, the movement of the lock member 107 in the P2 direction is prevented by the bearing hole 109a provided in the bearing portion 109, and the lock member 107 rotates. It becomes a rotational movement only of the movement (the state shown in FIG. 9).

Thereafter, when the second belt portion 5 of the seat belt 3 further moves in the direction P2, the lock member 107 rotates counterclockwise. However, the tip portion of the first portion 107b of the lock member 107 is more than Pmin than the position of Pmin.
Since it cannot move in the two directions, tightening and fixing of the second belt portion 5 of the seat belt 3 by the lock member 107 are realized at this portion (the state shown in FIG. 10).

Therefore, the direction in which the second belt portion 5 of the seat belt 3 tends to extend (the direction in which the child safety seat for the vehicle is loosened to the seat of the vehicle) is always set by the locking member 107. Second belt part 5
Since the fastening and fixing of the vehicle are working directions, the fixing state of the child safety seat for the vehicle to the vehicle seat is not released. Further, the fixing state can be easily realized by tightening the seat belt 3 in the P1 direction.

In order to release the state in which the child safety seat for the vehicle is fixed to the vehicle seat, the housing body 10
By releasing the opening / closing mechanism 1, it is possible to easily release the fixed state.

In the above-described embodiment, the housing main body 101 is the base 30 of the child safety seat for an automobile.
Although the structure is made rotatable with respect to the upper surface 31 of B, this structure is caused by the structure of the seat belt 3. For example, for a seat belt having one end in a free state,
Since the seat belt can be inserted into the gap between the housing main body and the upper surface of the base, it is also possible to adopt a structure in which the housing main body is fixed to the upper surface. It is also possible to provide a bracket or the like for supporting the lock member 107 on the base 30B.

The above embodiment describes a belt tightening device as a preferred embodiment, and thus employs a configuration in which the lock member 107 moves along the direction in which the second belt portion 5 of the seat belt 3 moves. However, the fastening of the second belt portion 5 of the seat belt 3 is possible even in a configuration that does not move.

The upper surface 31 is provided with a concave portion capable of receiving the lock member 107.
In the relationship with the lock member 107, the length (L1) from the center of the rotation support shaft 108, which is the center of rotation, to the tip end of the first side 107b is different from the center of the rotation support shaft 108 to the upper surface 31. The length (L2) from the center of the rotation support shaft 108, which is the center of rotation, to the tip of the first portion 107c is longer than the shortest distance (L3) to the center of the rotation support shaft 108. From the shortest distance to the upper surface 31 (L3:
The distance from the center of the rotation support shaft 108 to Pmin is shorter than the distance from the center of the rotation support shaft 108 to Pmin.
Any length that is longer than 1) and satisfies the condition that the distance from the center of the rotation support shaft 108 to the P2 direction side of Pmin is shorter than (L1) and longer than (L2).

In the belt fastening device having the above structure, there is a high possibility that a composite external force acts on the structure. In such a case, for example, when the belt tightening device is formed of a resin member, the strength is improved by providing a reinforcing member made of a metal material or the like in a portion where the external force acts intensively. Becomes possible.

As shown in FIG. 11, a belt hook 300 can be provided on the base 30B as an auxiliary device. The belt hook 300 will be described below.

The purpose of providing the belt hook 300 is as follows.
Of the components of the force applied to the belt fastening device 200 from the seat belt 3, the component of the approximately upward force is absorbed, so that only the force in the sliding direction of the seat belt 3 is applied to the belt fastening device 200. That's why.

As shown in FIG. 11, a specific structure of the belt hook 300 has a guide portion 300a, and a cut portion 300b for sliding the second belt portion 5 of the seat belt 3 into the guide portion 300a. Is provided.
The belt hook 300 is connected to the base 3 so that the cut 300b of the guide portion 300a is positioned lower than the portion where the second belt portion 5 is sandwiched by the belt fastening device 200.
0B.

By providing the belt hook 300 in this way, it is possible to reliably absorb the component of the force applied substantially upward from the component applied to the belt fastening device 200 from the seat belt 3.

Although the case where the belt hook 300 is provided in the vicinity of the belt fastening device 200 has been described with reference to FIG. 11, the belt fastening device is provided for the purpose of attaching the child safety seat for an automobile to the vehicle seat. It is preferable to provide it in the vicinity of 100 in advance.

As described above, the embodiments disclosed herein are illustrative in all aspects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

[0067]

According to the belt tightening device according to the present invention, the belt can be easily tightened after the belt is fixed, while the belt can be easily released. Can be performed.

According to the child safety seat for an automobile based on the present invention, the seat belt can be tightened at the second belt portion of the seat belt after the seat belt is fixed. It becomes possible to easily attach a car with a child safety seat.

Further, the direction in which the seat belt tends to extend (the direction in which the state of securing the child safety seat for the vehicle to the vehicle seat is loosened) is always the direction in which the fastening and fastening of the seat belt by the lock member work. Therefore, the state in which the child safety seat for the vehicle is fixed to the vehicle seat is not released, and the mechanism is effective for safety.

Further, of the components of the force applied from the seat belt to the belt tightening device, the component of the upward force is absorbed,
The belt tightening device further includes an auxiliary device for applying only the force in the sliding direction of the seat belt, so that the seat belt is securely fastened by the belt tightening device and a force is applied to the seat belt. It is possible to improve the safety of the child safety seat for a car when the vehicle is added.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing a structure of a belt fastening device according to an embodiment based on the present invention.

FIG. 2 is a first sectional view showing a structure of the belt fastening device corresponding to a section taken along line XX ′ in FIG. 1;

FIG. 3 is a second sectional view showing the structure of the belt fastening device corresponding to a section taken along line XX ′ in FIG. 1;

FIG. 4 is a first cross-sectional view showing a cross section of a lock member used for the belt tightening device and a tightened state of the belt.

FIG. 5 is a cross-sectional view for explaining a detailed cross-sectional structure of a lock member used for the belt fastening device.

FIG. 6 is a second sectional view showing a tightened state of the seat belt.

FIG. 7 is a third sectional view showing a tightened state of the seat belt.

FIG. 8 is a fourth sectional view showing a tightened state of the seat belt.

FIG. 9 is a fifth sectional view showing a tightened state of the seat belt.

FIG. 10 is a sixth sectional view showing a tightened state of the seat belt.

FIG. 11 is an overall perspective view showing a structure when a belt hook is used in a belt fastening device according to an embodiment based on the present invention.

FIG. 12 is a perspective view showing a tightened state of a seatbelt for fixing a child safety seat for a vehicle to a vehicle seat in the prior art.

[Explanation of symbols]

 2: Child safety seat for automobile 3: Seat belt 4: First belt part 5: Second belt part 6: Tongue plate 7: Buckle 30A: Seat part of child safety seat for automobile 30B: Child safety seat for automobile Base 31: Upper surface 31a: Curved surface 31b: Curved surface 31c: Step 32: Mounting surface 33: Shaft 34: Lock shaft 100, 200: Belt fastening device 100A: Housing member 101: Housing body 101a: Inner surface 101b: Convex portion 102 : Adjusting lever 103: Elastic part 104: Hook member 105: Tip part 106: Rear end part 107: Lock member 107 a: Uneven surface 107 b: First side 107 c: Second side 108: Rotation support shaft 109: Bearing part 109 a: Bearing hole 300: Belt hook 300a: Guide part 300b: Cut

Claims (23)

[Claims] 1. A fastening device that sandwiches a belt together with a main body and permits movement of the belt in a first direction in a longitudinal direction and does not allow movement in a second direction opposite to the first direction. A belt tightening device comprising: a belt tightening device rotatably supported by the main body, allowing the belt to slide in the first direction; A belt tightening device having a lock member for preventing sliding in two directions. 2. A cross section of the lock member along the direction in which the belt extends, a first portion on the first direction side that is longer than a distance from a rotation center to the main body, and a second direction. 2. The belt tightening device according to claim 1, further comprising a second portion on a side that is shorter than a distance from the rotation center to the main body. 3. The lock member has a rotation support shaft at both ends, and the rotation support shaft is supported by a long hole along the direction in which the belt moves. The belt tightening device according to 1. 4. The belt is allowed to slide in the first direction on a contact surface of the belt between the first portion and the second portion with the belt, and the belt is allowed to slide in the second direction. The belt tightening device according to claim 2 or 3, wherein an uneven surface for preventing sliding on the belt is provided. 5. The belt tightening device according to claim 1, wherein the main body includes a concave surface that can receive the lock member. 6. A fastening device that sandwiches a belt together with a main body and permits movement of the belt in a first direction in a longitudinal direction and does not allow movement in a second direction opposite to the first direction. A belt tightening device comprising: a belt tightening device, wherein the tightening unit is disposed in a direction intersecting with a moving direction of the belt, and one end side is rotatably attached to the main body; A housing member whose side is selectable between an open state and a closed state with respect to the main body; and, in order to sandwich the belt together with the main body, at a position facing the main body of the housing member, in a direction in which the belt moves. And a lock member rotatably mounted along the lock member and allowing the belt to slide in the first direction and preventing the belt from sliding in the second direction. 7. A cross-sectional shape of the lock member along the direction in which the belt extends, a first portion longer than a distance from a rotation center to the main body on the first direction side; The belt tightening device according to claim 6, further comprising a second portion that is shorter than a distance from the rotation center to the main body on the direction side. 8. The lock member has a rotation support shaft at both ends, and the rotation support shaft is provided on a bearing portion of the housing member and has a long length along a moving direction of the belt. 8. The belt tightening device according to claim 6, wherein the device is supported by a hole. 9. A contact surface of the belt between the first portion and the second portion with the belt allows the belt to slide in the first direction and the second direction. The belt tightening device according to claim 7 or 8, wherein an uneven surface that prevents sliding on the belt is provided. 10. The belt tightening device according to claim 6, wherein the main body includes a concave surface capable of receiving the lock member. 11. A child safety seat for a vehicle fixed to a seat of the vehicle using a seat belt provided on the vehicle, wherein the child safety seat for a vehicle is mounted on the vehicle using the seat belt. When the seat belt is fixed to a seat, the seat belt is sandwiched together with the main body of the child safety seat for an automobile in order to adjust the tightness of the seat belt, and the seat belt is moved in a first direction in the longitudinal direction. A child safety seat for a motor vehicle, comprising a belt fastening device having fastening means that allows for movement in a second direction opposite to the first direction. 12. The vehicle seat according to claim 1, wherein the seat belt includes a first belt portion extending from a lower side of a seat of the vehicle, and a tongue plate detachably fixed to a buckle receptacle provided on the vehicle. A three-point seat belt having a second belt portion extending upward, wherein the child safety seat for a vehicle has a mounting surface for passing the first belt portion of the seat belt, and the belt tightening. 12. An appliance is disposed near the mounting surface, on a side of the child safety seat for an automobile, away from the tongue plate, and provided so as to sandwich and fix the second belt portion. The child safety seat for automobiles described in. 13. The child safety seat for an automobile according to claim 12, wherein the mounting surface has a concave portion for receiving the seat belt. 14. The child safety seat for an automobile according to claim 12, wherein the belt tightening device has an openable and closable housing, and a tip portion is provided so as to protrude from the mounting surface. . 15. The belt fastening device according to claim 1, wherein the belt fastening device is provided on both sides of a main body of the child safety seat for an automobile.
15. The child safety seat for an automobile according to any one of 1 to 14. 16. The child safety device for an automobile according to claim 11, wherein the vehicle child safety seat has a seat portion and a base, and the belt fastening device is provided on the base. Safety seat. 17. A component of a force directed substantially upward from a component of a force applied from the seat belt to the belt fastening device, and the belt fastening device includes only a force in a sliding direction of the seat belt. 12. The child safety seat for a motor vehicle according to claim 11, further comprising an auxiliary device for allowing the vehicle to participate. 18. The vehicle seat according to claim 18, wherein the seat belt includes a first belt portion extending from a lower side of a seat of the vehicle and a tongue plate detachably fixed to a buckle receptacle provided on the vehicle. A three-point seat belt having a second belt portion extending upward, wherein the child safety seat for a vehicle has a mounting surface through which the first belt portion of the seat belt passes, and the belt tightening. The device is disposed in the vicinity of the mounting surface and on a side portion of the child safety seat for a car separated from the tongue plate, and is provided so as to sandwich and fix the second belt portion. 18. The child safety seat for an automobile according to claim 17, further comprising a guide portion for passing the second belt portion substantially upward from the belt tightening device. 19. The child safety for an automobile according to claim 18, wherein the auxiliary device is provided such that the guide portion is located below a portion where the second belt portion is sandwiched by the belt fastening device. seat. 20. The child safety seat according to claim 18, wherein the guide portion has a cut for sliding the second belt portion. 21. The vehicle child safety seat according to claim 17, wherein the vehicle child safety seat has a seat portion and a base, and the belt fastening device and the auxiliary device are provided on the base. Child safety seat for automobiles. 22. The child safety seat according to claim 21, wherein the belt fastening device is provided on an upper surface of the base, and the auxiliary device is provided on a side surface of the base. 23. The child safety seat for an automobile according to claim 22, wherein the belt tightening device is provided on both sides of an upper surface portion of the base, and the auxiliary device is provided on both sides of a side surface portion of the base.