The present invention relates to a seat load detecting apparatus for detecting a load acting on a seat, and in particular, relates to a seat load detecting apparatus in which a load sensor is provided inside a frame that constitutes a seat skeleton.
Conventionally, in the field of vehicles, in order to detect whether or not an occupant is seated on a seat by detecting a load acting on a seat cushion, cushion springs that give cushioning are disposed inside a seat cushion frame that forms a seat skeleton, the cushion springs are laid out across the seat cushion frame by springs from the left and right of a seat pan of the seat, and a load sensor is arranged on a member thereof (for example, see patent document 1).
In the above mentioned publication, the load sensor is fixed by a bolt to the inner side of the side portion of the seat cushion frame. The cushion springs have spring lines laid out on a plane lengthwise and breadthwise, and are formed of main members and a plurality of sub-members (coil springs) attached to the main members on their outer sides. The sub-members, which are the coil springs, have one end latched to the seat pan on either left or right side, respectively, of the main members, and the other end is latched to the seat cushion frame.
The configuration is such that when a person sits on the seat and a load acts on the seat cushion, the sub-members flex, so that the load sensor detects a pulling force from the sub-members. In such cases, in order that the flexure of one of the plurality of sub-members is detected, the load sensor is arranged at one sub-member.
Patent document reference 1: JP 2001-180353A
Problem to be Solved by the Invention
Conventionally, however, as in the above described publication, in a configuration in which the load sensor is arranged at one of the sub-members, part of the load acting on the cushion springs is detected by the load sensor, so that when a person sits on the seat, since the load acting on the cushion springs escapes to the seat cushion frame from locations other than sub-members to which the load sensor is connected, load detection cannot be performed with good accuracy. Therefore, although it would be desirable to arrange a load sensor for each cushion spring in order to perform load detection with good accuracy, costs would increase.
Thus, in view of the above described problems, the present invention has as a task the provision of a configuration in which load detection can be carried out with good accuracy while curtailing increased costs.
Means for Solving Problem
The technological means devised to solve the above described problems involves, for a seat load detecting apparatus for detecting, by a load detection means, a load acting on a seat, arranging a latching rod for latching a plurality of cushion springs, that give cushioning in the seat, to the inside of a seat cushion frame that forms a seat skeleton, the load detecting means being arranged between the latching rod and the seat cushion frame.
In such cases, the load detecting means may preferably be arranged as a pair with respect to the latching rod.
Furthermore, the load detecting means may be formed from a flexible member that is equipped with a load sensor, one end of the flexible member being supported by the seat cushion frame, and the latching rod being supported rotatably by the other end.
In addition, the load detecting means may have the load sensor provided internally and may be formed from a cylinder whose internal volume is variable, one end of the cylinder being supported by the seat cushion frame and the rod being rotatably supported by the other end, the internal volume being variable when the load acts.
The load sensor is preferably configured so that the load is detected by detection by a Hall element, or by a variation in a resistive element.
Furthermore, the technological means devised to solve the above described problems may include a seat load detecting apparatus for detecting, by a load detection means, a load acting on a seat, comprising a seat cushion frame that forms a seat skeleton, a flexible member for engaging with the seat cushion frame, a latching rod for latching the flexible member, and a plurality of cushion springs that engage with the latching rod, wherein a load sensor is attached to the flexible member.
In this regard, the latching rod is preferably provided at at least one of the front and the rear of the seat cushion frame, and is preferably provided at one side or at both sides of the seat cushion frame.
Moreover, the cushion springs preferably have a waveform profile.
Furthermore, the technological means devised to solve the above described problems may include a seat load detecting apparatus for detecting, by a load detection means, a-load acting on a seat, comprising a seat cushion frame that forms a seat skeleton, a flexible member that engages with the seat cushion frame, a latching rod for latching the flexible member, and a plate member linked to the latching rod and receiving the load acting on the seat, wherein the flexible member is equipped with a load sensor.
In this regard, the latching rod is preferably provided at at least one of the front and the rear of the seat cushion frame, and is preferably provided at one side or at both sides of the seat cushion frame.
Moreover, the seat cushion frame and the plate member are preferably engaged by a spring.
In addition, the latching rod and the plate member are preferably engaged by a spring.
Effects of the Invention
According to a first characteristic configuration of the invention, it is possible to perform collective latching by the latching rod for latching the plurality of cushion springs that give cushioning, and the load thus collected can be enlarged. Moreover, in load detection, since the load detecting means need not be provided for each of the cushion springs, a configuration is possible in which load detection can be performed at low cost, and in comparison to conventional cases, load that escapes to the seat cushion frame is lessened and it is possible to perform load detection with good accuracy.
According to a second characteristic configuration of the invention, the load detecting means is provided as a pair with respect to the latching rod. As a result, it is possible to support the latching rod at two holding positions, and it is possible to detect the load acting on the latching rod by a summation of the pair of load detecting means.
According to a third characteristic configuration of the invention, the load detecting means is formed from the flexible member equipped with a load sensor, one end of the flexible member is supported by the seat cushion frame, and the latching rod is rotatably supported by the other end. As a result, the load acting on the plurality of cushion springs is collected by the latching rod, the load acting on the cushion springs can be communicated to the load detecting means without stress on the way to the load detecting means, and the load detection can be performed with good accuracy.
According to a fourth characteristic configuration of the invention, the load detecting means is provided internally with a load sensor and is formed from a cylinder whose internal volume is variable, one end of the cylinder is supported by the seat cushion frame, the rod is rotatably supported by the other end, and when a load acts, the internal volume varies. As a result, the load acting on the cushion springs is communicated to the load detecting means, and the internal volume of the cylinder can vary according to the size of the load. Furthermore, by the load sensor detecting the varying state of the internal volume, it is possible to perform load detection with good accuracy.
According to a fifth characteristic configuration of the invention, the configuration is such that the load sensor detects the load by detection by a Hall element or by a variation in a resistive element. As a result, it is possible to realize a simple configuration in which the Hall element is provided inside the cylinder, a permanent magnet is provided at a position opposite the Hall element, and variations in magnetic flux are detected by the Hall element, or, the resistive element is formed on the inside face of the cylinder, and a brush is made to slide on the resistive element according to the size of the load.
According to a sixth characteristic configuration of the invention, since the plurality of cushion springs are engaged with the latching rod, the load that bears on the cushion springs is collected in the latching rod. The load collected in the latching rod is transmitted to the flexible member, and is detected by the load sensor that is attached to the flexible member. As a result, it is not necessary to provide a load sensor at each cushion spring and an implementation can be realized at low cost. Furthermore, in comparison to conventional seat load detecting apparatuses, load that escapes to the seat cushion frame is lessened, and load detection can be performed with good accuracy.
According to seventh and eighth characteristic configurations of the invention, the latching rod is provided at at least one of the front and the rear of the seat cushion frame, or is provided at one side or at both sides of the seat cushion frame. As a result, a distortion due to the load assuredly occurs between the latching rod and the seat cushion frame.
According to a ninth characteristic configuration of the invention, since the cushion springs are engaged with the latching rods at equal intervals, the load bearing on the cushion springs is transmitted uniformly to the latching rod.
According to a tenth characteristic configuration of the invention, since the transmitted load is concentrated on a curved portion of the flexible member, the distortion occurs most easily in this curved portion. As a result, it is possible to accurately detect the load, through the load detection sensor provided at the curved portion.
According to an eleventh characteristic configuration of the invention, the load bearing on the seat can be widely collected by the cushion springs, that have a waveform profile.
According to a twelfth characteristic configuration of the invention, since a plate member is engaged with the latching rod, the load bearding on the plate member is collected at the latching rod. The load collected at the latching rod is transmitted to the flexible member, and is detected by the load sensor attached to the flexible member. As a result, the load bearing on the seat can be widely collected by the plate member. Furthermore, in comparison to conventional seat load detecting apparatuses, load that escapes to the seat cushion frame is lessened, and load detection can be performed with good accuracy.
According to thirteenth and fourteenth characteristic configurations of the invention, since the latching rod is provided at at least one of the front and the rear of the seat cushion frame, or is provided at one side or at both sides of the seat cushion frame, the distortion due to the load occurs assuredly, between the latching rod and the seat cushion frame.
According to fifteenth and sixteenth characteristic configurations of the invention, since the seat cushion frame and the plate member are engaged by means of a spring, or the latching rod and the plate member are engaged by means of a spring, cushioning can be increased.
Best Mode for Carrying Out the Invention
Embodiments of the present invention are explained below, referring to the figures.
As shown in
The seat cushion frame 11 forming a seat skeleton for the seat pan 4 is made of a rigid body, with its inner portion exhibiting a rectangular shape and forming an opening. In the seat cushion frame 11, in order to maintain rigidity on the left and right of the rear of the seat pan 4, a linking rod 13 is arranged for both ends of the rear of the seat cushion frame 11.
Meanwhile, in order to provide cushioning in the opening 14 when a person sits on the seat cushion 3, a plurality of cushion springs 17 (for example, four springs in
The latching rod 15 is supported by the seat cushion frame 11 and attached, via the pair of flexible members 21 arranged at both left and right sides of the seat pan 4 at the front of the seat cushion frame 11.
The flexible members 21 (load detecting means at the front) detect a load at the front of the seat pan 4, and exhibit a shape shown in
In the flexible members 21, as shown in
Meanwhile, the flexible members 31 are arranged between the linking rod 13 and the latching rod 16 provided at the rear of the seat pan 4. The flexible members 31 are arranged as a pair on both left and right sides of the seat pan 4 at the rear of the seat cushion frame 11, and it is possible to detect a load at the rear of the seat pan 4 by the pair of flexible members 31.
The flexible members 31 (load detecting means at the rear) exhibit a shape shown in
As shown in
That is, the plurality of parallel cushion springs 17 have one end linked to the latching rod 15, and the other end linked to the latching rod 16, and the two latching rods 15 and 16 are supported at the front and rear by the pairs of flexible members 21 and 31 arranged on the left and the right sides. The state shown in
Next, operation for cases where a load acts on the seat are explained, referring to
From the state shown in
Furthermore, at the same time at the rear of the seat pan 4, the latching rod 16 that latches the rear end of the plurality of cushion springs 17 and lays them in rows, as shown in
Meanwhile, when the occupant leaves the seat cushion 3 and the load acting from above on the cushion springs 17 ceases to act, by means of the biasing force possessed by the cushion springs 17, the state shown in
In this way, for the configuration shown in
A structure for detecting the load acting on the seat pan 4, for the seat cushion frame 11, can obviously also be applied to the seatback frame 12 that forms the skeleton of the seatback 2, and more accurate load detection is possible at the seat backrest region as well. In these cases, with the plurality of cushion springs 17 provided in the front-rear direction for the seat pan 4 inside the seat cushion frame 11 and the cushion springs 20 having cushioning in the backrest region of the seatback frame 12 disposed in a left-right direction, comfort is improved. The plurality of cushion springs 20 (six in
(Embodiment 2)
Next, a configuration of Embodiment 2 will be explained. Embodiment 2 concerns a modified example of
In the configuration of Embodiment 1 shown in
(Embodiment 3)
Next, Embodiment 3 is explained, referring to
As shown in
By the fact that the internal volume of the load detecting apparatus 40 is variable, and the fact that the distance between the permanent magnet 45 and the Hall element 44, provided, respectively, at the principal member 41 and the moveable member 42, varies according to the position of the moveable member 42 with respect to the principal member 41, and that the flux from the permanent magnet 45 that passes through the Hall element 44 varies, load detection from the displacement amount is possible. In such cases, by adjusting the height of the cylinder 48, it is possible to adjust the flux detected by the Hall element 44.
This type of load detecting apparatus 40 has a configuration in which, in the front, for example, the principal member 41 is fixed by a bolt or the like to the back of the periphery of the opening 14 of the seat cushion frame 11, and the latching rod 15 that receives the front load of the seat pan 4 is supported by the moveable member 42. Meanwhile, in the rear, as shown in
Consequently, as shown in
Furthermore, as another modified example, as shown in
(Embodiment 4)
Embodiment 4 is shown in
In Embodiment 4, a load receiving plate 30, being a plate member formed of a rigid body, is arranged inside the seat cushion frame 11, and the load-receiving plate 30 is supported by each of a plurality of coil springs 27 and 28 from both the front and rear, with respect to the seat cushion frame 11. Even with a configuration in which in the rear, a load acting on the rear of the seat is received via the same latching rod 16 as in
(Embodiment 5)
Embodiment 5 is shown in
In the field of vehicles, the invention is applicable in a seat load detecting apparatus in which a load sensor is arranged inside a frame constituting a seat skeleton.
Number | Date | Country | Kind |
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2003-282992 | Jul 2003 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP04/10655 | 7/27/2004 | WO | 11/30/2005 |