JPH07186727A - Back door opening/closing mechanism for automobile - Google Patents

Abstract

PURPOSE:To provide a back door opening/closing mechanism which can make the holding force to be at maximum at full opening of a back door and become in the compact received condition at full opening and closing of the back door. CONSTITUTION:This back door opening/closing mechanism is provided with a door side link member 6 of which one end is rotationally movably connected to a back door 1, a vehicle body side link member 8 of which the lower end is rotationally movably connected to a vehicle body 2 and the upper end is rotationally movably connected to the other end of the door side link member 6, and a damper stay 11 of which the lower end is rotationally movably connected nearly coaxially to the lower end connected part 7 of the body side link member 8 and the upper end is rotationally movably connected to the middle part in the lengthwise direction of the door side link member 6. At full opening and full closing of the back door 1, the door side link member 6, the body side link member 8, and the damper stay 11 are arranged along the nearly same straight line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back door opening / closing mechanism for an automobile, and more particularly, to a back door opening / closing mechanism for an automobile constructed so that a damper stay expands and contracts with the opening / closing movement of the back door.

[0002]

2. Description of the Related Art As an opening / closing mechanism for a back door mounted on an automobile, for example, as shown in FIG. 6, an opening / closing fulcrum 5 for a back door 52 is provided near an upper edge of an opening 51 behind a vehicle body 50.
There is generally known a configuration in which the damper stays 54, 54 are provided between the back door 52 and the vehicle body 50 by providing 3, 53.

The damper stay 54 has a cylinder 54a filled with compressed gas and a piston rod 54b held in the cylinder 54a so that the piston rod 54b can move back and forth. The upper end of the damper stay 54 is supported by an inner surface of the back door 52. 52a is rotatably connected to the lower end of the opening 5 of the vehicle body 50.
It is rotatably connected to one side edge via a support shaft 50a.

The damper stay 54 is a back door 52.
The expansion of the cylinder causes the gas in the cylinder 54a to expand and the pressure to drop. However, the gas pressure at the time of this decrease surely supports the back door 52 in the fully open position. I need to put it. Therefore, the gas pressure in the cylinder 54a in the non-fully opened state must be made higher than necessary.

[0005]

By the way, the operating force of the back door 52, that is, the force required to close the back door 52, due to the above-mentioned changing state of the gas pressure of the damper stay 54, is shown in FIG. As indicated by the characteristic curve A, the maximum value is obtained at the predetermined position A1 during the opening / closing operation, and the maximum value is decreased at the time point A2 when the fully opened state is achieved.

Therefore, when the back door 52 is closed, there is a problem that the operation force becomes maximum and heavy in the middle of A1 and the smooth closing operation is hindered.

Further, with the above characteristics, for example, the back door 52 is stopped at an arbitrary position within a predetermined range during opening and closing by making the operating force zero within a predetermined range during opening and closing. Then, the holding force at the fully open position becomes zero or less, which causes a problem that the back door 52 cannot be maintained in the fully open state.

Japanese Utility Model Laid-Open No. 58-54322 discloses a structure in which one end of a damper stay is indirectly connected to a back door via two link members and the other end is connected to a vehicle body. There is. Specifically, as shown in FIG. 8, an upper end of a damper stay (a gas stick link in the publication) S whose lower end is connected to the vehicle body B and whose lower end is connected to the vehicle body B at its longitudinal middle portion. To connect
The other end of the vehicle body side link BL is connected to the other end of the door side link DL, one end of which is connected to the back door D.

According to this structure, even if the angle formed by both links BL and DL and the angle formed by the damper stay S when the back door D is fully closed are set to be small to some extent, as shown in FIG. As shown, these angles increase as the back door D opens. Then, the angle formed by the damper stay S and the vehicle body side link BL at the time of full opening is close to 90 degrees.

Therefore, judging from the change state of the gas pressure of the damper stay S as described above, the maximum operation force (holding force) cannot be obtained when the back door D is fully opened, and in the same manner as described above. The operation becomes heavy during the closing of the back door D, or the back door cannot be stopped at an arbitrary position during the opening / closing operation.

Further, according to the configuration disclosed in the publication, the connecting portion of the damper stay S to the vehicle body B is arranged at a distance from the back door D forward by a long dimension, and the vehicle body link BL has the vehicle body B. Is connected to the vehicle body B of the damper stay S at a distance above the connecting portion to the vehicle body B.

Therefore, when the back door D is fully closed and fully opened, the links BL and DL and the damper stay S are not in a compact state, which causes a space problem in the rear portion of the vehicle body.

The present invention has been devised under the above-mentioned circumstances, and the holding force can be maximized when the back door is fully opened, and is compact when the back door is fully closed and fully opened. It is an object of the present invention to provide a back door opening / closing mechanism that can achieve the above.

[0014]

In order to solve the above problems, the present invention takes the following technical means.

That is, the invention according to claim 1 of the present application is a back door of an automobile constructed so that the damper stay expands and contracts in accordance with the opening and closing movement of the back door having an opening and closing fulcrum near the upper edge of the opening at the rear of the vehicle body. In the opening / closing mechanism, one end is rotatably connected to a back door, a lower end is rotatably connected to a vehicle body, and an upper end is rotatably connected to the other end of the door side link member. And a vehicle body side link member, a lower end of which is rotatably connected substantially coaxially with a lower end connecting portion of the vehicle body side link member, and an upper end of which is rotatably connected to a longitudinal intermediate portion of the door side link member. And the door-side link member, the vehicle-body-side link member, and the damper stay are arranged along substantially the same straight line when the back door is fully closed and fully opened. To have.

The invention described in claim 2 of the present application is
The door-side link member is connected to the vehicle body-side link member when the back door is opened, with the door-side link member centering on the line that connects the longitudinal intermediate portion of the door-side link member to the straight line that connects the two ends of the door-side link member. Is characterized in that it is deviated by a predetermined dimension on the side opposite to the direction of rotation.

[0017]

The main features of the back door opening / closing mechanism according to the present invention are that the upper end of the damper stay is connected to the longitudinal intermediate portion of the door side link member, and the lower end of the damper stay and the lower end of the vehicle body side link member are connected. Is to be connected to the vehicle body substantially coaxially. The door-side link member, the vehicle-body-side link member, and the damper stay are configured to be arranged along substantially the same straight line both when the back door is fully closed and when it is fully opened. .

More specifically, when the door-side link member and the vehicle-body-side link member are folded with the connecting portion between them being a fulcrum when fully closed, both link members gradually expand as the back door opens. When it is opened and fully opened, it is in a state of being expanded and arranged along a substantially straight line.

Therefore, when the back door is fully opened, the respective connecting portions of the door side link member and the vehicle body side link member to the back door and the vehicle body, the connecting portions between these link members, and the door side link of the damper stay. The connecting portion to the member will be substantially aligned.

As a result, even if a force in the closing direction acts on the door-side link member from the back door, both link members are in a state in which it is difficult to rotate about the connecting portion between them, and this state is the state of the damper stay. Since it is maintained by the action of gas pressure, the holding force for holding the back door in the fully open position becomes large as a result.

As described above, according to the invention of the present application, the holding force at the fully opened position of the back door is increased by effectively utilizing the form of both link members when the back door is fully opened. It becomes possible to maximize the holding force at this fully open position after reducing the operating force at.
Therefore, when the back door is closed, the problem that the closing operation becomes heavy at a predetermined position after starting the closing motion does not occur. Also, when the back door is fully opened and fully closed, both link members and the damper stay are arranged in a substantially straight line and compactly housed.
Restrictions on the space behind the vehicle body, such as the loading space and the loading / unloading work space, are alleviated.

Further, as in the case of claim 2,
The door-side link member is centered around the connecting portion with the vehicle-body-side link member when the back door is opened, with respect to the straight line connecting the connecting portions at the longitudinal middle portion of the door-side link member to the connecting portions at both ends of the door-side link member. Further effects can be obtained by deviating by a predetermined dimension on the side opposite to the rotating direction. That is, by displacing in such a direction, immediately before the back door reaches the fully open position, the connecting portion at the longitudinal intermediate portion of the door side link member is connected to the back door of the door side link member and the vehicle body side link member. It is possible to set it so as to cross the straight line connecting the respective connecting portions to the vehicle body. By making such a setting, the operating force sharply increases when the back door opens and reaches the vicinity of the fully open position, and a very large holding force can be obtained when fully opened compared to other positions. become.

Along with this, even if the gas pressure of the damper stay is set so that the operating force becomes zero within a predetermined range at other positions, it is possible to secure a predetermined holding force of zero or more when fully opened. become. As a result, for example, when a short child or the like opens and closes the back door, the back door can be stopped and held at an intermediate position of the opening operation, and even if the back door cannot be opened to the fully open position, There is no obstacle to loading and unloading.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a back door opening / closing mechanism for an automobile according to the present invention will be specifically described below with reference to the drawings.

As shown in FIG. 1, the back door 1 has its upper end portion openably and closably attached via an opening / closing fulcrum 3 near the upper edge of the opening at the rear of the vehicle body 2, and its middle portion is a back door. It is connected to the vehicle body 2 via a door opening / closing mechanism 4.

The back door opening / closing mechanism 4 has a door side link member 6 whose rear end is rotatably connected to the back door 1 through a door side support shaft 5, and a lower end of the door side link member 6 attached to the vehicle body 2. And a vehicle body side link member 8 rotatably connected to each other via 7. The front end of the door side link member 6 and the upper end of the vehicle body side link member 8 are rotatably connected via a support shaft 9.

An upper end of a damper stay 11 is rotatably connected to an intermediate portion in the longitudinal direction of the door side link member 6 through an intermediate support shaft 10, and a lower end of the damper stay 11 is connected to the vehicle body side support shaft. It is rotatably connected to the vehicle body via 7. Therefore, in this embodiment, the lower end of the damper stay 11 and the lower end of the vehicle body side link member 8 are coaxially connected to the vehicle body 2. The lower ends may be connected to different shafts at substantially the same position. In addition,
As described above, the damper stay 11 includes the cylinder 11a filled with gas and the piston rod 11b biased in the protruding direction by the gas pressure.

The dimensions of the link members 6, 8 and the damper stay 11, the mounting positions of the door side support shaft 5 and the vehicle body side support shaft 7, and the disposition position of the intermediate support shaft 10 in the door side link member 6 are as follows. Is set to.

That is, when the back door 1 shown in FIG. 2 is fully closed, the door side link member 6 and the vehicle body side link member 8 are provided.
And are in a folded state, and both the link members 6 and 8 and the damper stay 11 are arranged along substantially the same straight line. On the other hand, when the back door 1 shown in FIG. 3 is fully opened, the door-side link member 6 and the vehicle-body-side link member 8 are in an expanded state, and both the link members 6 and 6.
8 and the damper stay 11 are set so as to be arranged along substantially the same straight line.

Further, as shown in FIG. 1, the intermediate support shaft 10, which is the connecting portion of the damper stay 11 to the door side link member 6, has the door side support shaft 5 and the vehicle body side support shaft at both ends of the door side link member 6. The straight line L1 connecting the shaft 7 is displaced by a predetermined dimension a. Specifically, the intermediate support shaft 10 is deviated to the side opposite to the direction in which the door-side link member 6 rotates about the support shaft 9 when the back door 1 is opened.

According to the above construction, when the back door shown in FIG.
Since they are arranged so that they will overlap, the paste paste 11
The force of the gas pressure in the extension direction is applied to the vehicle body side link member 8
Absorbed by. This allows the back door 3 to be fully closed.
It is possible to prevent a large amount of force from acting on.

On the other hand, when the back door shown in FIG. 3 is fully opened,
The intermediate support shaft 10 of the door side link member 6 moves to the opposite side beyond the straight line L2 connecting the door side support shaft 5 and the vehicle body side support shaft 7.

The back door opening / closing mechanism 4 which operates as described above changes the operating force as indicated by reference character Y in FIG. 4 from the time of fully closing to the time of fully opening. Compared with the conventional characteristic curve A, the characteristic curve Y does not show a peak in the operating force at a position slightly before the fully open position Y2, and the characteristic curve Y suddenly increases as indicated by a symbol Y1 from the time when the operating force reaches the vicinity of the fully open position. The operating force increases to the maximum at the fully open position Y2.

As a result, the back door 1 is supported with the maximum holding force at the fully open position, and the disadvantage that the operation becomes heavy during the closing of the back door 1 can be avoided.

Further, by utilizing the above characteristic curve Y, FIG.
As shown in, the predetermined range Y during the opening and closing movement of the back door 1
Dampen stay 1 so that the operating force becomes zero in x.
Even if the gas pressure of 1 is set, a predetermined holding force of zero or more can be obtained at the fully open position Y2. This allows
For example, when a short child or the like opens and closes the back door 1, the back door 1 can be stopped and held at an arbitrary position in the middle of the opening operation, and even if the back door 1 cannot be opened to the fully open position, the luggage can be opened. It will be possible to smoothly load and unload.

In the above embodiment, the door side link member 6 is used.
Although the intermediate support shaft 10 is displaced in a specific direction with respect to a straight line connecting the support shafts 5 and 9 at both ends thereof, the intermediate support shaft 10 is temporarily not displaced or is arranged in the vicinity of a straight line. If so, the holding force becomes maximum at the fully-opened position Y2, even if the sudden increase portion as shown by the symbol Y1 in FIG. 4 does not appear, and the operation force becomes maximum at the middle A1 of the opening / closing path as in the conventional case. Can be avoided.

More specifically, regardless of the eccentric state of the intermediate support shaft 10, both link members 6 and 8 are arranged on substantially the same straight line at the fully opened position of the back door 1, so that both link members are arranged. 6 and 8 are difficult to rotate,
In addition, since this difficult rotation state is maintained by the gas pressure of the damper stay 11, the holding force for holding the back door 1 becomes maximum at the fully open position.

In addition, regardless of the eccentric state of the intermediate support shaft 10, when the back door 1 is fully closed, the constituent elements are arranged along substantially the same straight line as shown in FIG. , The space behind the vehicle body is not restricted. Further, even when the back door 1 is fully opened, the constituent elements are arranged along substantially the same straight line as shown in FIG. 3, so that these constituent elements are an obstacle when loading and unloading luggage. It becomes possible to minimize such a situation.

[Brief description of drawings]

FIG. 1 is a schematic side view of essential parts showing an embodiment of a back door opening / closing mechanism according to the present invention, showing a state in which the back door is being opened / closed.

FIG. 2 is a schematic side view of essential parts showing a state when the back door is fully closed in the embodiment.

FIG. 3 is a schematic side view of essential parts showing a state in which the back door is fully opened in the above embodiment.

FIG. 4 is a graph showing an example of change characteristics of the operating force according to the above embodiment.

FIG. 5 is a graph showing another example of change characteristics of the operating force according to the above-mentioned embodiment.

FIG. 6 is a schematic perspective view showing a conventional example.

FIG. 7 is a graph showing a change characteristic of operating force according to a conventional example.

FIG. 8 is a schematic side view showing an operation of a conventional example.

FIG. 9 is a schematic side view showing an operation of a conventional example.

[Explanation of symbols]

 1 Back Door 2 Car Body 3 Opening / Closing Support Point 4 Back Door Opening / Closing Mechanism 5 Door Side Support Shaft 6 Door Side Link Member 7 Body Side Support Shaft 8 Body Side Link Member 9 Support Shaft 10 Intermediate Support Shaft 11 Damper Stay

Claims (2)

[Claims] 1. A back door opening / closing mechanism for an automobile, wherein a damper stay expands / contracts in accordance with opening / closing movement of a back door having an opening / closing fulcrum near an upper edge of an opening at the rear of a vehicle body. A door-side link member that is freely connected, a lower end that is rotatably connected to the vehicle body, and an upper end that is rotatably connected to the other end of the door-side link member, and a lower end that is the vehicle body. A rear link member which is rotatably connected substantially coaxially with a lower end connecting portion of the side link member and has an upper end rotatably connected to a longitudinal middle portion of the door side link member, and the back door is fully closed. A back door opening / closing mechanism for an automobile, wherein the door-side link member, the vehicle-body-side link member, and the damper stay are configured to be arranged along substantially the same straight line at the time of fully opening. 2. A door-side link member is connected to a vehicle-body-side link member when the back door is opened, with respect to a straight line connecting a connecting portion at a longitudinally intermediate portion of the door-side link member to a connecting portion between both ends of the door-side link member. 2. The back door opening / closing mechanism for an automobile according to claim 1, wherein the back door opening / closing mechanism is deviated by a predetermined dimension on the side opposite to the direction of rotation about the connecting portion.