Patent Application
20090218978
The present invention relates to a contact detection apparatus and a pinch prevention apparatus, particularly to an apparatus that detects contact with an object and a pinch prevention apparatus that detects that two members, at least one of which is driven by a driver, pinch a foreign object and controls the driver to prevent the pinch.
A power window of a vehicle or the like is configured in such a way that a window regulator moves a pane back and forth between the positions where the window frame is open and closed. The window regulator is controlled to prevent the body or the like of a driver or a passenger from being pinched. As an example of such control, a detector provided in the vicinity of the window frame is used to prevent pinch based on a detection signal from the detector.
The detector includes an elastically flexible tube in which a pair of parallel electrodes are disposed in such a way they face each other with a gap therebetween. The detector detects pinch when the tube is crushed to cause a short circuit between the electrodes (see JP-A-61-45518, for example) or decrease in the distance between the electrodes and hence increase in capacitance (see JP-A-2000-329506, for example).
Patent Document 2: JP-A-2000-329506
The detector does not produce a detection signal until the tube is sufficiently crushed. There is therefore a delay in initiating the pinch prevention control after pinch occurs, so that the body or the like is kept severely pinched during the delay period.
An object of the invention is to provide a contact detection apparatus that allows faster detection. Another object of the invention is to provide a pinch prevention apparatus equipped with such a detection apparatus.
The invention according to claim 1 to achieve the above objects is a contact detection apparatus characterized in that the apparatus includes a first electrode made of a flexible conductive material and extending throughout a contact detection range, a second electrode apart from the first electrode and extending on the back side of the first electrode, and detection means for detecting contact of an object with the first electrode based on the capacitance of the first electrode.
The invention according to claim 2 to achieve the above objects is the contact detection apparatus according to claim 1, characterized in that the first electrode is made of a conductive resin containing an embedded conductor.
The invention according to claim 3 to achieve the above objects is the contact detection apparatus according to claim 2, characterized in that the embedded conductor is located at the base of the first electrode.
The invention according to claim 4 to achieve the above objects is the contact detection apparatus according to claim 2 or 3, characterized in that the embedded conductor is an embedded metal.
The invention according to claim 5 to achieve the above object is the contact detection apparatus according to any one of claims 1 to 4, characterized in that the detection means detects the contact when the capacitance of the first electrode becomes greater than a predetermined threshold value.
The invention according to claim 6 to achieve the above objects is the contact detection apparatus according to claim 5, characterized in that the second electrode has a capacitance greater than the threshold value.
The invention according to claim 7 to achieve the above objects is the contact detection apparatus according to claim 5, characterized in that the detection means also detects the contact when the capacitance of the first electrode becomes smaller than another threshold value that is smaller than the threshold value.
The invention according to claim 8 to achieve the above objects is the contact detection apparatus according to claim 7, characterized in that the second electrode is a grounded electrode.
The invention according to claim 9 to achieve the above objects is the contact detection apparatus according to claim 8, characterized in that the second electrode is made of a conductive material.
The invention according to claim 10 to achieve the above objects is the contact detection apparatus according to claim 9, characterized in that the conductive material is a metal.
The invention according to claim 11 to achieve the above objects is the contact detection apparatus according to claim 9, characterized in that the conductive material is a conductive rubber.
The invention according to claim 12 to achieve the above objects is the contact detection apparatus according to claim 9, characterized in that the conductive material is a conductive resin.
The invention according to claim 13 to achieve the above objects is the contact detection apparatus according to claim 12, characterized in that the conductive resin contains an embedded conductor.
The invention according to claim 14 to achieve the above objects is the contact detection apparatus according to claim 13, characterized in that the embedded conductor is an embedded metal.
The invention according to claim 15 to achieve the above objects is the contact detection apparatus according to claim 13 or 14, characterized in that the first and second electrodes are integrally formed with an insulating resin for a joint purpose by using extrusion molding.
The invention according to claim 16 to achieve the above objects is a pinch prevention apparatus including a detection apparatus that detects that two members, at least one of which is driven by a driver, pinch a foreign object and a control apparatus that controls the driver to prevent the pinch based on a pinch detection signal from the detection apparatus, the pinch prevention apparatus characterized in that the detection apparatus is the contact detection apparatus according to any one of claims 1 to 15.
In the inventions according to claims 1 or 16, since the contact detection apparatus includes the first electrode made of a flexible conductive material and extending throughout a contact detection range, the second electrode apart from the first electrode and extending on the back side of the first electrode, and the detection means for detecting contact of an object with the first electrode based on the capacitance of the first electrode, a contact detection apparatus that allows faster detection and a pinch prevention apparatus equipped with such a detection apparatus are achieved.
In the invention according to claim 2, since the first electrode is made of a conductive resin containing an embedded conductor, the isoelectric state of the first electrode can be enhanced.
In the invention according to claim 3, since the embedded conductor is located at the base of the first electrode, the load exerted by the first electrode when it is deformed is small.
In the invention according to claim 4, since the embedded conductor is an embedded metal, isoelectricity can be enhanced.
In the invention according to claim 5, since the detection means detects the contact when the capacitance of the first electrode becomes greater than a predetermined threshold value, contact with the human body is easily detected.
In the invention according to claim 6, since the second electrode has a capacitance greater than the threshold value, contact with an object having a low capacitance can be detected.
In the invention according to claim 7, the detection means also detects the contact with an object having a low capacitance when the capacitance of the first electrode becomes smaller than another threshold value that is smaller than the threshold value.
In the invention according to claim 8, since the second electrode is a grounded electrode, the capacitance can be reduced when the second electrode comes into contact therewith.
In the invention according to claim 9, since the second electrode is made of a conductive material, the second electrode is reliably grounded.
In the invention according to claim 10, since the conductive material is a metal, isoelectricity can easily be achieved.
In the invention according to claim 11, since the conductive material is a conductive rubber, the formation is easily carried out.
In the invention according to claim 12, since the conductive material is a conductive resin, the formation is easily carried out.
In the invention according to claim 13, since the conductive resin contains an embedded conductor, isoelectricity can easily be achieved.
In the invention according to claim 14, since the embedded conductor is an embedded metal, isoelectricity can easily be achieved.
In the invention according to claim 15, since the first and second electrodes are integrally formed with an insulating resin for a joint purpose by using extrusion molding, the integrated structure is easily handled.
The best mode for carrying out the invention will be described below in detail with reference to the drawings. The invention is not limited to the best mode for carrying out the invention.
The window 100 includes a pane 102. The window regulator 200 includes a lifting/lowering motor 202 and a lifting/lowering mechanism 204. The lifting/lowering motor 202 drives the lifting/lowering mechanism 204 to lift and lower the pane 102. The safety device 300 manages the safety of the lifting/lowering operation of the pane 102 performed by the window regulator 200.
The safety device 300 is an example of the best mode for carrying out the invention. The configuration of the safety device 300 shows an example of the best mode for carrying out the invention concerning the pinch prevention apparatus.
The safety device 300 includes a CPU 302. The CPU 302 is the heart of the safety device 300 and performs the safety management of the window regulator 200 based on a predetermined program. The CPU 302 uses a drive circuit 304 to control the lifting/lowering motor 202. The amount of rotation of the lifting/lowering motor 202 is fed back to the CPU 302 via a pulse generator 306 and a counter 308. The CPU 302 recognizes the position of the pane based on the count obtained in the counter 308.
A vehicle having a plurality of power windows includes a plurality of sets of the window 100 and the window regulator 200, and a plurality of sets of the pulse generator 306, the counter 308, a sensor 320, and a contact detector 330 are provided accordingly.
The CPU 302 receives a pane lifting/lowering command via a switch 310. The switch 310 is operated by a user. The switch 310 includes a plurality of switches corresponding to the plurality of windows. These switches are collectively provided in an area close to the driver's seat, so that any of the plurality of windows can be opened and closed from the driver's seat.
The sensor 320 is provided in the window 100. The output signal from the sensor 320 is inputted to the contact detector 330. The contact detector 330 judges whether or not contact with an object occurs based on the output signal from the sensor 320 and inputs a judgment signal to the CPU 302. The CPU 302 controls the window regulator 200 based on the input signal from the contact detector 330.
The portion formed of the sensor 320 and the contact detector 330 is an example of the best mode for carrying out the invention. The configuration of this portion shows an example of the best mode for carrying out the invention concerning the contact detection apparatus. The contact detector 330 is an example of the detection means in the invention.
The window frame 104 includes an upper frame 104a, a rear frame 104b, and a front frame 104c. The upper frame 104a is roughly horizontal. The rear frame 104b is inclined roughly rearward and downward. The front frame 104c is roughly vertical. The sensor 302 is disposed along the upper frame 104a and the rear frame 104b.
The sensor 320 includes an outer electrode 430 and an inner electrode 440 integrally formed via a joint member 450 therebetween. The outer electrode 430 is an example of the first electrode in the invention. The inner electrode 440 is an example of the second electrode in the invention. The joint member 450 is, for example, made of insulating resin, such as thermoplastic olefin elastomer (TPO). The sensor 320 is attached to the door sash 140 by using the U-shaped portion of the joint member 450.
The outer electrode 430 and the joint member 450 form a tubular structure, and the inner electrode 440 is supported by the joint member 450 at the upper center of the inner wall of the tubular structure. The inner electrode 440 is as long as the external electrode 430. In this text, the outer-wall side of the tubular structure is also referred to as the front side, and the inner-wall side is also referred to as the back side. The inner electrode 440 is therefore located on the back side of the outer electrode.
The outer electrode 430 is made of a flexible conductive material. Examples of such a material are conductive rubber and conductive resin. An example of conductive resin is carbon-containing TPO.
The outer electrode 430 includes an embedded metal 432 in its base, that is, in the vicinity of the portion where the outer electrode 430 is connected to the joint member 450. The embedded metal 432 is a wire made of stainless steel or copper extending entirely along the outer electrode 430. Having the embedded metal 432, the outer electrode 430 has the same potential throughout its length. The embedded metal 432 may be replaced with a conductor other than a metal. Examples of such a conductor may be conductive resin and conductive rubber with particularly enhanced conductivity.
The outer electrode 430 is connected to the contact detector 330 through a signal line. The contact detector 330 detects whether or not the outer electrode 430 comes into contact with the human body based on the capacitance of the outer electrode 430. The detection whether or not there is contact is carried out with reference to a predetermined threshold value.
The inner electrode 440 is also made of a conductive material. An example of such a material is conductive resin. The inner electrode 440 includes an embedded metal 442. The embedded metal 442 is a wire made of stainless steel or copper extending entirely along the outer electrode 440. The embedded metal 442 may be replaced with a conductor other than a metal. Examples of such a conductor may be conductive resin and conductive rubber with particularly enhanced conductivity.
Having the embedded metal 442, the inner electrode 440 has the same potential throughout its length. The embedded metal 442 can be omitted. The inner electrode 440 is connected to the door sash 140. The inner electrode 440 may be connected to the ground of the electric system that forms the safety device 300. In this case, the inner electrode 440 becomes a ground electrode.
The thus configured sensor 320 is integrally molded, for example, by using extrusion molding. In this way, the sensor 320 formed of the outer electrode 430, the inner electrode 440, and the joint member 450 can be easily manufactured.
The contact detector 330 detects the pinching based on the increase in capacitance. A pinch detection signal is inputted to the CPU 302. The CPU 302 controls the drive circuit 304 to lower the pane 102 based on the pinch detection signal.
The pinch prevention operation is initiated as soon as the human body comes into contact with the sensor 320 without any delay. Further, since the outer electrode 430 of the sensor 320 is flexible, no large force is exerted on the pinched human body.
When an object having a low capacitance is pinched, the capacitance of the outer electrode 430 may not become greater than the threshold value in some cases. Such a situation occurs, for example, when the hand wearing a glove is pinched. In this case, the contact between such an object and the sensor 320 alone will not initiate the pinch prevention operation.
Instead, the pane 102 keeps rising with the object pinched, and the outer electrode 430 is crushed and comes into contact with the inner electrode 440, as shown in
The contact detector 330 also judges that contact occurs when the capacitance is instantly reduced (removed). The contact detection in response to instant reduction (removal) in capacitance is based on another threshold value. The threshold value is smaller than that used for detecting increase in capacitance.
Based on the contact detection using these threshold values, the pinch prevention operation is carried out under the control of the CPU 302. In this way, even when an object having a low capacitance is pinched, the pinch prevention operation can be reliably carried out.
The inner electrode 440 is not necessarily be a ground electrode but may be an electrode having a high capacitance. In this case, the capacitance of the outer electrode 430 will become greater than the threshold value when it comes into contact with the inner electrode 440, allowing detection of contact with an object. When the inner electrode 440 has a capacitance, the embedded metal 442 may be omitted.
In
In
In
In
The operation of the present apparatus will now be described.
It is judged in the step 605 whether or not pinching may have occurred. When it is detected that no pinching may occur, it is judged in the step 607 whether or not the pane has reached the dead point. When the pane has not reached the dead point, the process returns to the step 603. Until it is detected that pinching may occur or the pane has reached the dead point, the operations described in the steps 603 to 607 are repeated. During these operations, the pane keeps rising. When it is detected that no pinching may occur but the pane has reached the dead point, the process proceeds to the step 611 and waits a command of the next action.
When it is judged in the step 605 that it is detected that pinching may occur, the pane is stopped or moved in the reverse direction in the step 609. The detection that pinching may occur is based on the detection by the sensor 320 that contact with the human body or the like has occurred, as shown in
When the object that has come into contact is, for example, a bare hand, the contact is detected as shown in
While the above example has been described with reference to a power window for a vehicle, the power window is not limited thereto, but may be any power window as long as it uses a window regulator to drive the pane. While the above description has been made with reference to a power window that lifts the pane to close the window frame, the power window to be used may lower the pane to close the window frame. Alternatively, the power window may move the pane in the horizontal direction or in an oblique direction to close the window frame. Further, a power window is not necessarily used, but a power-driven sunroof, sliding door, back door, a pivoted door, or the like may be used.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-298853 | Oct 2005 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2006/320332 | 10/11/2006 | WO | 00 | 12/31/2008 |
